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This study aims to clarify the growth process of the β-phase in Al-Mg-Si alloys from the point of view of morphological evolution. The orientation relationship, shape, growth process, misfit value, and interfacial condition between the β-phase and Al matrix were investigated using high-resolution transmission electron microscopy (HR-TEM), focused ion beam (FIB), and optical microscope (OM). In a previous study, the growth process and shape of the β-phase were determined using scanning electron microscopy (SEM). It was proposed that the truncated octahedron (8{111}, 6{100} facets) transforms into a hexahedron (6{100} facets). This study proposes that two new three-dimensional shapes of the β-phase exist between the truncated octahedron and hexahedron, and we identified the {111} β facets at the edges of the β-phase. We proposed the morphology evolution during the growth process of Mg 2 Si crystals and calculated the misfit to understand that the unstable {111} β facet has a higher misfit value compared to the {001} β and {011} β facets. Our observations provide insight into how they influence the behavior of Mg 2 Si crystals, which is crucial for predicting the microstructural evolution of Al-Mg-Si alloys and for designing materials with desired properties. • Investigated the morphology evolution of the β-phase in Al-Mg-Si alloys. • Explored β-phase orientation relationship, shape, and growth process using HR-TEM, FIB, and OM. • Discovered {111} β facets and proposed new three-dimensional shapes for the β-phase. • Calculated misfit values, revealing the instability of the (111) β facet compared to (001) β and (011) β facets. • Contributed to understanding microstructural evolution in Al-Mg-Si alloys and material design. [ABSTRACT FROM AUTHOR]

ZrN and TiNiN nanolayers are alternately deposited on silicon substrate by magnetron sputtering. A series of ZrN/TiNiN nano-multilayer films with different Ni contents are prepared by varying the Ni:Ti volume ratio of the targets. The effects of Ni content on the microstructures and mechanical properties of ZrN/TiNiN nano-multilayer films are studied by X-ray diffractometer (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and nanoindentation instrument. The results show that with the increase of Ni content, the crystallization degree of ZrN phase first increases and then decreases. Besides, the hardness, elastic modulus and toughness of the films also increase first and then decrease with Ni content increasing. When Ni:Ti= 1:24, the ZrN/TiNiN nano-multilayer films obtain the highest hardness, elastic modulus and fracture toughness, which are 23.2 GPa, 317.8 GPa and 2.29 MPa·m1/2, respectively. This is mainly attributed to the best columnar crystal growth of the ZrN/TiNiN nano-multilayer film. The TiNiN layer changes into face centered cubic structure under the template of ZrN layer, and grows in coherent epitaxy with ZrN layer. ● A series of ZrN/TiNiN nano-multilayer films with different Ni contents are prepared by magnetron sputtering. ● When Ni:Ti= 1:24, the ZrN/TiNiN nano-multilayer films simultaneously obtain the highest hardness and fracture toughness. ● The high hardness and toughness are due to that the TiNiN layer grows in coherent epitaxy under the ZrN layer template. [ABSTRACT FROM AUTHOR]

We report on the one-step synthesis of vertically aligned multiwalled carbon nanotubes (MWCNTs) filled with Co magnetic nanowires via bias-assisted plasma enhanced chemical vapor deposition (PECVD) method. Co/Pd bilayer, both of nanometric thicknesses, deposited onto 50 nm thick TiSiN serving as a diffusion barrier was used as catalysts for nanotube growth. The process gas was a mixture of acetylene (carbon source) and ammonia. A 6 mbar growth pressure combined with 200 W plasma power permitted to achieve simultaneously the growth, alignment and filling of the carbon nanotubes. The plasma was activated by applying a negative bias between − 500 and − 600 V to the substrate. Structural investigations of 1D cobalt rich nanocrystals confined in vertically aligned carbon nanotubes were carried out by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) to elucidate the growth mechanisms. Statistical analysis was performed on the nanotubes peeled from the forest and dispersed. Spatially resolved electron energy loss spectroscopy (EELS) and energy filtered elemental mapping revealed that the nanotubes are mainly filled with cobalt X-ray photoelectron spectroscopy (XPS) confirmed the presence of Co, Pd, C, N and O, with weak degrees of oxidation of the metallic Co and carbide Co formation. Hysteresis cycles, from vibrating sample magnetometer (VSM) measurements at room temperature, exhibited a ferromagnetic behavior with coercive field H C values well above those usually reported for continuous layers. H C is also observed to be higher when the Co nanoparticles embedded in the CNTs exhibit nail shape than spherical or cylindrical one. This can be explained by a lower mean diameter. This shape aspect influences the nature of the magnetization reversal probably operating through curling process. These results open up the potential for one step growth, alignment and filling of carbon nanotubes with potential applications as spintronic devices. [Display omitted] • One step plasma enhanced CVD growth and filling of carbon nanotubes with cobalt. • Nanotube growth and filling was improved by using Co and Pd bilayer catalyst deposited onto TiSiN diffusion barrier. • Control of filling was performed by varying substrate temperature, applied bias and plasma power. • Confined 1D cobalt rich nanowires network with lengths up to 5 µm and aspect ratio up to 20 was obtained. • Magnetic properties of embedded nanowires are shape dependent and enhanced regarding to catalyst film. [ABSTRACT FROM AUTHOR]

We report a study on the growth of NiBi 3 nanowires and nanorods during the preparation of superconducting NiBi 3 films by co-evaporation of Ni and Bi. We find that NiBi 3 films grown via co-evaporation of Ni and Bi metals achieve higher transition temperatures (4.4 K) compared even to the single crystal NiBi 3. However, in certain parameter space, the film surfaces were spattered with nanoscale features, such as nanowires and nanorods. Ambient temperature deposition resulted in poly-crystalline NiBi 3 nanorods which were controllable with the evaporation rate of Bi. Deposition at elevated temperatures promoted the emergence of long single crystalline NiBi 3 nanorods. High resolution transmission electron microscopy measurements confirmed the crystalline behaviour of the nanorods. We believe that NiBi 3 nanowires form in a process analogous to the well known vapor-liquid-solid process, as we observe an amorphous Bi cap on the nanorods. From glancing angle X-ray diffraction measurements we identify that the presence of trigonal Bi with hexagonal primitive cell in the film promotes the nucleation of nanorods. Electrical transport on a single NiBi 3 nanowire shows a superconducting transition of 4.3 K. [Display omitted] • Demonstrated a one-step physical route for obtaining single crystal, superconducting nanorods of NiBi3. • Identified that the rhombohedral phase of Bi in the film of NiBi3 promotes the nucleation of the NiBi3 nanorods. • HRTEM shows that the process of single crystal nanorod growth is similar to the VLS route of growth of nanowires. [ABSTRACT FROM AUTHOR]

The phase analysis and average crystallite size of 11.8, 3.1, and 24.7 nm for MFe 2 O 4 (M=Co, Ni, Zn) nanoparticles (NPs) were analyzed by X-ray diffraction (XRD) patterns, respectively. The spherical and nanoplatelets morphology of MFe 2 O 4 (M=Co, Ni, Zn) was observed by High-Resolution Transmission electron microscopy (HRTEM). The peaks of Fe (2 P 3/2), Fe(2 P 1/2), Co (2 P 3/2), Co(2 P 1/2), Ni (2 P 3/2), Ni (2 P 1/2), Zn (2 P 3/2), Zn (2 P 1/2) and O (1 S) of the prepared nanostructures corresponding to octahedral and tetrahedral sites was observed X-ray photoelectron spectroscopy (XPS) spectra, respectively. Saturation magnetization of 37.4, 18.2, and 15.3 (emu/g) and coercive field of 525, 35.2, and 29.7 Oe of the prepared MFe 2 O 4 (M=Co, Ni, Zn) nanostructures was recorded by M-H analysis at the applied field of ± 7 T. The shifting of the blocking temperature towards lower scale of about 300 K, 150 K, and 55 K for CoFe 2 O 4 , NiFe 2 O 4 , and ZnFe 2 O 4 nanostructures was determined by Zero field-cooled (ZFC) and field-cooled (FC) spectra, respectively. Spin-spin relaxation time 0.1677 × 10−15, and 0.0482 × 10−15 (s) and Spin-lattice relaxation time 0.829 × 10−14, and 2.865 × 10−14 (s) have been evaluated for NiFe 2 O 4 and Zn Fe 2 O 4 NPs, respectively from EPR spectroscopy. Super-paramagnetic time of 0.134 × 10−10, and 5.703 × 10−10 (s) was estimated from the EPR spectrum of the samples exhibiting less time required for NiFe 2 O 4 than ZnFe 2 O 4 NPs. The prepared NPs showing the superparamagnetic property can be used in biomedical applications such as drug delivery and magnetic resonance imaging (MRI). [Display omitted] • Observation of nanoparticles and nanoplatelets by high resolution transmission electron microscopy. • Electron paramagnetic resonance spectroscopy to estimate the relaxation times. • Estimation of spin-spin relaxation and spin lattice relaxation times of NiFe 2 O 4 and ZnFe 2 O 4 NPs. • They can be used for drug delivery and magnetic resonance imaging (MRI) applications. [ABSTRACT FROM AUTHOR]

Copper indium disulfide (CuInS 2) single crystals are prepared by the chemical vapour transport technique and characterised by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), and high resolution transmission electron microscopy (HRTEM). The XRD outcome reveals tetragonal lattice structure. The EDS result confirms that the sample is near stoichiometry, while the FESEM and HRTEM micrographs show multilayered opaque crystals. The lattice fringe arrangement reveals d -spacing of 0.32 nm, which matches the d -spacing of primary peak (112) of XRD. Electrical resistivity value decreases as temperature varies from 303 K to 423 K, confirming the crystal is semiconducting. The negative signs in the Hall coefficient (−8.49 × 105 cm3·C−1) and Seebeck coefficient (−148 μV·K−1) confirm n-type nature. The maximum figure of merit (zT) is predicted as 3.99 × 10−4 at 423 K. It suggests that CuInS 2 has the prospective to be used in thermoelectric power generation. [Display omitted] • CuInS 2 single crystals synthesised by the CVT technique. • Study of transport properties of the single crystals. • The crystals are n-type semiconductors. • The synthesized crystals showed good thermoelectric figure of merit. [ABSTRACT FROM AUTHOR]

Carbon nanotube reinforced titanium (CNT/Ti) composites with high tensile strength (872 ± 5 MPa) were synthesized by the high pressure torsion process (HPT). C s -corrected high resolution transmission electron microscopy (TEM) revealed face centered cubic titanium (FCC–Ti) distributed in the grains and at the grain boundaries of a hexagonal close packed titanium (HCP–Ti) matrix, with an orientation relationship of [0002] HCP //[11 1 ¯ ] FCC and {2 1 ¯ 1 ¯ 0} HCP //{011} FCC between FCC-Ti and HCP-Ti. The phase transformation from a HCP-Ti structure to a FCC-Ti structure in the CNT/Ti composites during the HPT process made a significant impact on the mechanical properties. Combining experimental results with density functional theory calculations, the stability of FCC-Ti and HCP-Ti under external pressure were analyzed. Moreover, the nucleation and growth mechanisms of FCC-Ti phase in HCP-Ti matrix were identified. The results showed that the stress-induced phase transformation from HCP-Ti to FCC-Ti in the CNT/Ti composites during the HPT process is associated with the source of Shockley partial dislocations. This work helps to the better understanding of the phase transformation mechanism from a HCP-Ti structure to a FCC-Ti structure in CNT/Ti composites. • FCC-Ti were reviewed in CNT/Ti composites by HR-TEM, with an orientation relationship of [0002] //[11] and {20} //{011} • Combining experimental results with calculations, the stability of FCC-Ti and HCP-Ti under external pressure were analyzed. • Phase transformation of HCP-Ti to FCC-Ti is associated with the source of Shockley partial dislocations. • The contribution of phase transformations in Ti matrix to enhance the mechanical properties of CNT/Ti composites was studied. [ABSTRACT FROM AUTHOR]

Undecorated and Pt-decorated SnO 2 nanoparticles (NPs) were prepared using sol-gel and hydrothermal methods. The tin dioxide NPs, as sensing materials, were screen printed on alumina substrates with Pt test electrode to fabricate the gas sensors. The characteristics of these gas sensors in terms of composition, morphology, and sensing property were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and electrochemical workstation, respectively. The results elucidated that the response time of Pt-decorated SnO 2 sensor to 100 ppm H 2 is 29 s at 350 °C, which is almost half of that of pure SnO 2 gas sensor. Meanwhile, the effect of operating temperature and Pt decorating on the sensing properties and the 'n' value is studied. Comparing with many fabricated H 2 gas sensors, our as-prepared sensor exhibits not only a high response time but also detects H 2 gas down to 0.08 ppm. To the author's best knowledge, the detection limit of 0.08 ppm is the best reported detection limit for the gas sensors based on tin oxide NPs so far. Moreover, there is a significant enhancement in the selectivity of Pt-decorated SnO 2 sensor to the H 2 gas against other investigated gases such as carbon monoxide (CO), methane (CH 4), nitrogen dioxide (NO 2), sulfur dioxide (SO 2). Overall, the obtained results clearly demonstrate that the Pt-decorated SnO 2 is an excellent sensing material for the fabrication of gas sensors and the detection of trace concentration of H 2 down to 0.08 ppm. Furthermore, the results of statistical and fractal analysis on 2D microstructures of FESEM images showed a coefficient correlation of about 0.991 for all the samples. • Pt-SnO 2 was synthesized using sol-gel and hydrothermal techniques. • The influence of 'n' value on the sensing properties of the fabricated gas sensors is discussed in details. • Pt-SnO 2 gas sensors demonstrated excellent sensing properties and can detect H 2 down to 0.08 ppm. [ABSTRACT FROM AUTHOR]

Herein, a one-step thermal evaporation was used for fabrication of silver bismuth selenide (AgBiSe 2) thin films of various thickness. The influence of thickness on the structural, optical and electrical properties of AgBiSe 2 thin films has been studied. The X-ray diffraction confirmed single hexagonal structure of deposited AgBiSe 2 thin films. The average grain sizes D and microstrain ε of deposited AgBiSe 2 films were estimated by Williamson-Hall (W-H) relation. The grain size increases from 11.52 to 29.12 nm as the thickness was increased from 150 to 550 nm, whereas strain dislocation density (ξ) and the number of crystallites N tends to decrease with thickness. The selected area electron diffraction pattern (SAED) obtained by high resolution transmission electron microscopy (HRTEM) verified the polycrystalline nature of samples and it is found to nearly agree with X-ray diffraction data. The elemental composition measurement of the as-deposited AgBiSe 2 thin film showed that the as-deposited film is near stoichiometric in compound. The influence of film thickness on the optical parameters of the AgBiSe 2 thin films, such as refractive index n , extinction coefficient k , real dielectric ε 1 , imaginary dielectric constant ε 2 , skin depth and the optical band gap, E g has been studied. It is found that the values of energy gap decrease from 1.88 to 1.68 eV with increasing thickness, while the values of Urbach energy follow an opposite trend. The electrical conductivity was measured by four-probe experiment in the range from 300 to 500 K. The analysis of dc conductivity data revealed the presence of two distinct regions with two various slopes confirming the transformation from hexagonal phase to rhombohedral phase at about 460 K. • AgBiSe2 thin films of various thicknesses were deposited by thermal evaporation. • XRD and HRTEM show that films formed in a pure single hexagonal structure. • The thresholding image displays the gradual increase of grain size with thickness. • The band gap energies changed from 1.88 to 1.68 eV with increasing thickness. • Dc conductivity confirms the transformation from hexagonal to rhombohedral phase at 460 °C. [ABSTRACT FROM AUTHOR]

Hydrothermal synthesis as a commonly bottom-up growth method has considerable advantages for manufacturing thermoelectric nanomaterials with advanced thermoelectric properties. However, the hydrothermally synthesized thermoelectric nanostructures often show a low thermoelectric performance due to their low power factor. In this work, we report on using a hydrothermal method for the growth of n-type Bi 2-x Sb x Se 3 nanoflakes with a fixed thickness of ∼16 quintuple-layers. The controlling of the stoichiometric composition, phase purity and crystallinity of the Bi 2-x Sb x Se 3 nanoflakes are demonstrated by the X-ray diffraction, Raman spectroscopy, and high resolution transmission electron microscopy. We further prove that adding of antimony into Bi 2 Se 3 compound mostly influences the in-plane vibration mode. The optical energy gap is sharply increased as the Sb content increases. The effect of the antimony incorporation on the electrical conductivity, Seebeck coefficient and power factor of Bi 2-x Sb x Se 3 nanoflakes is systematically investigated. The Bi 1.92 Sb 0.08 Se 3 sample is found to have the highest power factor ∼13.17 μW/cm.K2 at 470 K which is much higher than those published for other various nanostructured or bulk Bi 2 Se 3 compounds. The results propose a great prospect for further enhancing the thermoelectric power factor of the Bi 2 Se 3 nanostructures synthesized by this hydrothermal method. Taking into consideration the progress in Bi–Se compounds, the results of this work advocate the promise of Bi–Se nanostructures towards producing high performance thermoelectric devices. • Bi 2- xSbxSe3 (x = 0–0.08) nanoflakes(NFs) were prepared via a facile hydrothermal method. • The synthesis conditions were optimized to produce NFs of ∼16 QLs in thickness. • The effect of Sb doping on the optical and thermoelectric properties is investigated. • A power factor(PF) ∼13.17 μW/cmK2 at 470 K is obtained for the Bi 1.92 Sb 0.08 Se 3 sample. • The enhanced PF candidates the nanoflakes for promising thermopower applications. [ABSTRACT FROM AUTHOR]

Bi 2 S 3 nanoparticles (NPs) decorated ZnO nanorods' (NRs') heterostructures on glass substrate were prepared by varying the number of Bi 2 S 3 coatings by aqueous chemical growth and SILAR techniques and their ultraviolet sensing properties were investigated. X-ray diffraction and high resolution transmission electron microscopy results confirm phase purity of the individual components and formation of the heterostructure respectively. The photoluminescence properties reveal a gradual improvement in the ultraviolet (UV) to visible emission intensity ratio up to a certain number of Bi 2 S 3 coating due to comparatively a more decrease in the visible emission intensity. Highly enhanced UV photocurrent (∼7 times) and responsivity (∼6 times) values as compared to uncoated ZnO NRs have been noticed. Further, a very low intensity UV illumination of power density ∼21 μW/cm2 can be detected by ZnO-Bi 2 S 3 heterostructure more efficiently as compared to pristine ZnO NRs which is attributed to an efficient charge transfer at ZnO and Bi 2 S 3 interface. Image 1 • ZnO-Bi 2 S 3 heterostructure is formed using ACG and SILAR techniques. • Bi 2 S 3 nanoparticles decorated over ZnO nanorods making heterostructure. • Enhanced UV photoresponsivity in heterostructure is due to efficient charge transfer. • Demonstration of low-intensity light sensible and low-power operable efficient ZnO-Bi 2 S 3 UV detector. [ABSTRACT FROM AUTHOR]

The development of the clean synthesis of efficient bimetallic Pt-Pd alloy nanoparticles supported reduced graphene oxide (RGO) catalyst (RGO/Pt-Pd) through a facile, rapid, surfactant–free and novel one-pot process of chemical reduction-assisted hydrothermal reaction using formic acid as reducing agent have been introduced. The structural, elemental composition analysis and surface morphology of the as-prepared catalysts were extensively characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, energy dispersive x-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM), respectively. The electrochemical properties, catalytic activity and long-term stability performance of the RGO/Pt-Pd nanocomposite catalyst were employed by cyclic voltammogram and chronoamperometry. Furthermore, owing to the synergetic effects of Pt and Pd nanoparticles, the unique structure of Pt-Pd alloy nanoparticles and enhanced electron transfer by RGO, the as-synthesized RGO/Pt-Pd nanocomposite catalyst has demonstrated the enlarged electrochemical surface area (ECSA) (ECSA = 0.91 cm2), remarkably higher electro-catalytic activity (I f = 59.6 mA/cm2) and enhanced stability as compared to RGO/Pt (I f = 23.32 mA/cm2, ECSA = 0.18 cm2) and RGO/Pd (I f = 8.65 mA/cm2, ECSA = 0.11 cm2) nanocomposite catalysts toward methanol oxidation reaction (MOR). This superior catalytic activity of the as-prepared RGO/Pt-Pd nanocomposite catalyst with facile and simple preparation approach is promising a great opportunity for the development of direct methanol fuel cell. • RGO/Pt-Pd was produced by novel one-pot hydrothermal-assisted chemical reduction. • This one-pot hydrothermal-assisted chemical reduction method is effective, rapid and simple. • Formic acid was used as soft and non-metal reductant in the reaction process, without any surfactant or template. • Uniform Pt-Pd alloy nanoparticles supported on RGO formation were confirmed by HRTEM, XRD and XPS. • The as-synthesized nanocomposites exhibit superior catalytic activity and enhanced stability for methanol oxidation. [ABSTRACT FROM AUTHOR]

Recently, due to their high capacity and excellent cycle stability, bimetallic transition-metal oxides have attracted great interest from researchers for use as anode materials in lithium ion batteries. The main disadvantages of bimetallic transition-metal oxides are poor conductivity and easy aggregation during charge and discharge. Here, Co-based metal-organic frameworks (MOFs) are compounded with amorphous titanium oxide by a solvothermal reaction. After the high-temperature alloying of the precursor, carbon-coated CoTiO 3 nanocrystallites are synthesized. CoTiO 3 nanocrystallites coated by amorphous carbon not only improve the conductivity of the material but also effectively inhibit the aggregation of the CoTiO 3 nanocrystallites during charge and discharge. A total of 1400 cycles were cycled at a high current density of 2000 mAg−1, and the reversible capacity was maintained at 610 mAhg−1. In addition, cycling 100 cycles at the current density of 100 mAg−1 reveals the reversible capacity of 630 mAhg−1. Thus, the anode demonstrates excellent lithium storage performance. Then, we characterized the material composition, morphology and specific surface area by means of X-ray diffraction, high resolution transmission electron microscopy and nitrogen adsorption-desorption experiments. These experiments confirmed the unique structure of cobalt-coated CoTiO 3 nanocrystallites and excellent lithium storage performance. • MOF-derived synthesized carbon-coated ilmenite CoTiO 3 nanocrystallines were firstly synthesized for anode of Li-ion battery. • A relatively uniform coating of amorphous carbon prevents the CoTiO 3 nanocrystallites from aggregating during the charge-discharge processes. • After 1400 cycles at a high-density current of 2000 mAg−1, this composite releases reversible capacity of 610 mAhg−1. [ABSTRACT FROM AUTHOR]

Aiming to improve the rate capability and cycling stability, cesium doped Li-rich cathode materials Li 1.2-x Cs x Ni 0.13 Co 0.13 Mn 0.54 O 2 (x = 0, 0.012, 0.036, 0.060, 0.096) are synthesized by a sol-gel method and a subsequent calcination process. The optimal Cs+ content is found to be x = 0.060. After Cesium doping to Li+ sites, the enlarged interplanar spacing of (003) plane, which is confirmed by high resolution transmission electron microscopy, can accelerate the Li+ diffusion during the lithiation/delithiation process at the interface of electrode/electrolyte. The obtained Cs-doped Li-rich sample with x = 0.060 exhibits much improved electrochemical performance compared with the bare, especially the rate capability (148 mAh g−1 compared to 50 mAh g−1 at 10 C). The first discharge capacity is much enhanced from 250 to 281 mAh g−1 at 0.1 C with a heightened coulombic efficiency from 72% to 81%. XRD, SEM, TEM, elemental mapping, EDS and ICP-AES are adopted to characterize the morphologies and structures. • Cesium is successfully doped to Li+ sites in Li-rich cathode material. • Both rate and cycling properties are enhanced for Li 1.14 Cs 0.06 Ni 0.13 Co 0.13 Mn 0.54 O 2. • A variety of techniques are adopted to elucidate the improvement mechanism. [ABSTRACT FROM AUTHOR]

Abstract In this study, in-situ phosphorus-doped Si 1 − x C x layers were epitaxially grown on blanket and patterned Si wafers using reduced pressure chemical vapor deposition (RPCVD). The effect of post-growth annealing on the strain and microstructures of the epilayers was investigated by high resolution X-ray diffraction (HR-XRD), Raman scattering, and high resolution transmission electron microscopy (HR-TEM) analyses. Structural investigation revealed that induced tensile strain became significantly less at temperatures over 900°, as confirmed by Raman scattering measurements of Si C vibration modes. Furthermore, strain relaxation and substantial C sub loss were found in XRD and Raman data of Si:C samples annealed at 1000°, resulting from the generation of defects such as β-SiC precipitates or dislocations in Si 1 − x C x epilayers. Moreover, our microstructural analyses using TEM showed the formation of the β-SiC precipitates during rapid thermal annealing (RTA) over 900° and an increase in their number and size with annealing temperatures up to 1000°. Finally, we examined the impact of thermal annealing on the local strain and microstructures of patterned Si 1 − x C x samples with different structures. Our findings will provide greater insight into evaluating the strain states and microstructure of as-grown and annealed P-doped Si 1 − x C x films on both blanket and patterned Si wafers. Highlights • In-situ P-doped Si 1−x C x films were grown on Si substrates using a RPCVD system. • The impact of thermal annealing on the strain and microstructures was examined. • Significant loss in induced tensile strain was confirmed by XRD and Raman measurements. • TEM analyses provided direct evidence of the microstructural changes in the films. [ABSTRACT FROM AUTHOR]

The C f /ZrB 2 -SiC composite was successfully fabricated via brushing nano ZrB 2 -SiC slurry followed by low-temperature hot pressing technique, in which the UHTC phases were uniformly introduced into intrafascicular space of the subdivided fiber bundles. The fabricated composite exhibited a non-brittle fracture behavior and excellent mechanical properties with a high work of fracture of 1338 J/m2, one order of magnitude higher than that of the ZrB 2 -SiC ceramic, which was attributed to the hybrid toughening mechanisms such as crack deflection, fiber bridging, fiber pull-out and crack branching. The fiber/matrix interfaces were analyzed by the high resolution transmission electron microscopy, and no obvious chemical reaction was detected, suggesting the degradation of carbon fiber was effectively inhibited. Moreover, the C f /ZrB 2 -SiC composite showed a good thermal shock resistance with a thermal shock temperature difference of 764 °C, almost twice those of the ZrB 2 -SiC ceramic. This work provides a facile and effective approach to fabricate high-performance continuous carbon fiber reinforced ceramic composites with uniform component distribution. • The C f /ZrB 2 -SiC composite was prepared by nano slurry brushing and hot pressing. • The degradation of fiber was inhibited by low sintering temperature (1450 °C). • The outstanding work of fracture of 1338 J/m2 was achieved. • The thermal shock temperature difference was up to 764 °C. [ABSTRACT FROM AUTHOR]

Abstract Cracking carbon, grapheme as well as carbon nanotube co-modified LiVPO 4 F material (LiVPO 4 F/C/G/CNT) and cracking carbon modified LiVPO 4 F material (LiVPO 4 F/C) were respectively prepared by a two-step process. Physicochemical properties, electrochemical datas and kinetic parameters of LiVPO 4 F/C/G/CNT and LiVPO 4 F/C materials were obtained by various detection means. X-ray diffraction analysis (XRD) demonstrates that co-modification of multi-level carbon cannot change fundamental crystallographic structure of LiVPO 4 F/C/G/CNT material. Scanning electron microscopy (SEM) and High resolution transmission electron microscopy (HRTEM) synergistically reveal that cross-linked network structures formed by cracking carbon, grapheme and carbon nanotube are evenly distributed among the LiVPO 4 F particles, helping for charge transfer throughout the inside and outside of cathode materials. Compared with LiVPO 4 F/C material, the LiVPO 4 F/C/G/CNT material possesses many advantages such as higher discharge specific capacity, higher charge-discharge rate performance, smaller charge transfer impedance (Rct), and higher Li+ diffusion coefficient (D Li +), indicating that the LiVPO 4 F/C/G/CNT cathode material prepared by a two-step process shows better potential application prospect for lithium batteries. Highlights • Multi-level carbon co-modified LiVPO4F cathode material was synthesized. • An ideal architecture hybrid cathode material with multi-dimensional electron/ion diffusion channels was constructed. • Compared with LiVPO 4 F/C material, LiVPO 4 F/C/G/CNTs composite exhibits higher rate capability and cycling stability. [ABSTRACT FROM AUTHOR]

Abstract A combination of high resolution transmission electron microscopy (HRTEM) and electron backscatter diffraction (EBSD) was applied to study the formation mechanism associated with high index twins in a deformed magnesium alloy. Utilizing the information obtained about the formation of high index twins by identifying their structural characteristics and interfacial atomic arrangement, we found that high index twins were obtained from dislocation-modified double twins. With increasing deformation, misorientations between the matrix and deformation twin increased, resulting in the evolution of double twins into a variety of structures. This discovery about high index twin formation can greatly improve the ability to identify various types of double twins in EBSD data. This mechanism provides a new insight into the formation of high index twins and aids in understanding the material fractures caused by double twinning. Graphical abstract Image 1 Highlights • The interface atomic arrangements of high index twins were firstly investigated. • The process of dislocation-modified double twinning promotes the formation of a variety of high index twins. • A variety of high index twins can be obtained by different deformation strains. • A method for improving identification capability of various types of double twinning in EBSD maps is proposed. [ABSTRACT FROM AUTHOR]

The 2D-TMDC (transition metal dichalcogenides) formed thin films have attracted more attention due to their tuneable optoelectronic properties that improved the application of the photo-sensing device. SnSe single crystals were grown in the current work utilising the direct vapour transfer (DVT) technique. The elemental proportion and 2D surface structural analysis of grown crystal SnSe are carried out using Energy-dispersive X-ray analysis (EDAX) and Scanning electron microscopy (SEM). The orthorhombic crystal system of grown SnSe confirmed by high resolution transmission electron microscopy (HRTEM), and Powder X-ray diffractometer (XRD), the regular spot patter of HRTEM and Sharp pick in XRD graph indicated that the SnSe are highly crystalline in nature. The X-ray photoelectron spectroscopy (XPS) is carried out for confirming the binding states and chemical composition of grown SnSe single crystal. The A 1g , β 3g and A 2g vibration mode of SnSe single crystal confirmed using Raman Spectroscopy. In the application part, SnSe exhibits high photodetection capability under the monochromatic and polychromatic light sources at self-bias mode (photoresponsivity of 71.20 µA/W and photo-detectivity of 3.45 × 108 Jones). The optoelectronic characteristics of SnSe devices including dependent photo-responses have also been carried out. Additionally, the important factors affecting photodetection characteristics are assessed, including photocurrent (I ph), sensitivity (S), photoresponsivity (R), Specific detectivity (D*), rise time, and decay time. • we used a catalyst-free direct vapor deposition approach to grown a single crystal of SnSe. • The EDAX analysis shows that there are no contaminants in the generated material, and the mapping demonstrates the uniform distribution of all constituent elements. • The HR-TEM image showed the various lateral sizes of thin layers. The single-crystalline character of the SnSe samples is confirmed by SAED. • The XRD pattern of SnSe bulk crystals atoms were arranged in an orthorhombic crystal structure with a Pcmn space group. For SnSe, the crystal lattice parameters were a = 4.439 Å, b = 4.152 Å, and c = 11.470 Å. • The resonances corresponding to vibrational modes are seen in the Raman spectrum. • XPS was performed to confirm the formation of the SnSe structure. • The SnSe device shows the higher photodetection performance under all the monochromatic light sources at self-bias with photoresponsivity of 71.20 µA/W and photo-detectivity of 3.45 × 108 Jones Under a 650 nm light source, the device demonstrated good detection capability. For 0.005 V external bias, the device shows the highest photoresponsivity compared to other external biases under 650 nm illumination. [ABSTRACT FROM AUTHOR]

In this work, a cost-efficient Fe-based metallic glass in the Fe 74 B x Si y C z Nb 2 (x + y + z = 24) composition range with low electrical and thermal conductivity is developed. Ingots with different alloy compositions are produced from high-purity Fe, B, Si, C, Nb powders in a tube furnace and processed into metallic ribbons by melt spinning. The high content of various metalloids in the compositions is expected to enhance the electrical resistivity and lower the thermal conductivity in the amorphous phase. The thermophysical properties and the amorphous structure of the ribbon samples are investigated by x-ray diffractometry (XRD), differential scanning calorimetry (DSC), dilatometry (DSD) and high resolution transmission electron microscopy (HRTEM). The investigations confirm that the characteristic temperatures T g , T m , T x and T l of the alloy and thus its GFA are strongly dependent on the atomic composition. A particularly good glass forming ability (GFA) is achieved with the alloy composition Fe 74 B 8 Si 12 C 4 Nb 2. In addition to that a high hardness of 984 HV0.1 and a thermal conductivity as low as 6.41 W/mK is observed. It is concluded that metallic glasses in the Fe 74 B x Si y C z Nb 2 (x + y + z = 24) composition range can be considered as a cost-effective coating material for thermal insulation in a temperature range below T g ≈ 540 °C, as well as electrical components and wear protection. [Display omitted] • Development of alloy with highest GFA in Fe 74 B x Si y C z Nb 2 -Composition range. • High GFA at γm = 0.64, Trg = 0.611. • Low electrical and thermal conductivity; 2.6 μΩm and 6.41 W/mK. • Low-alloyed, cost-efficient composition. [ABSTRACT FROM AUTHOR]

In this study, biomass carbon supported with iron and cobalt bimetal (FeCo/BC) was synthesized by a one-pot calcination method to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) for bisphenol A (BPA) degradation. Characterization with X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy showed that Fe0, Fe 3 O 4 , Co0 and CoO nanocrystals were included in FeCo/BC materials. The degradation results showed Fe 0.6 Co 0.4 /BC had excellent catalytic activation performance for PMS or PDS. The Fe 0.6 Co 0.4 /BC (0.0050 g) combined with 0.25 g·L−1 of PMS could completely degrade 20 mg·L−1 BPA within 8 min, and the same amount of BPA could be removed with 0.020 g Fe 0.6 Co 0.4 /BC in the presence of 0.25 g·L−1 PDS within 20 min. The corresponding total organic carbon removal rates reached 83.49% and 77.5% respectively after 2 h. The Fe 0.6 Co 0.4 /BC also had good adaptability to solution pH and practical water body. After five cycles, the degradation rates of BPA in the two systems were all over 90%, and excellent magnetism was beneficial to the reuse of catalysts. Electron paramagnetic resonance and free radical quenching tests indicated that SO 4 •-, •OH, and 1O 2 were the main active species involved in the BPA degradation. This work not only provided a promising catalyst for the degradation of organic pollutants, but also elucidated the synergistic effect between Fe-Co bimetal alloys during PMS and PDS activation, which would facilitate the design, synthesis, and application of catalytic materials with high efficiency. [Display omitted] • The FeCo/C material was prepared through one-pot calcination method. • The FeCo/C exhibited high efficiency and feasibility for bisphenol A degradation by activating persulfate. • The synergistic effect between Fe and Co redox cycles played an important role for persulfate activation. • Electron paramagnetic resonance determination indicated that SO 4 •-, · OH, and 1O 2 were the main active species. [ABSTRACT FROM AUTHOR]

In this paper, W-33.3 at% Zr super-saturated solid solution powder was prepared by mechanical alloying, and its formation mechanism and thermal stability were systematically studied. After 30 h of milling, 33.3 at% of Zr was completely dissolved in W, and a super-saturated solid solution with BCC structure was formed. When the milling duration was increased to 50 h, the single BCC phase was transformed into a dual-phase mixture with a super-saturated solid solution and an amorphous phase. Thermodynamic calculations based on Miedema theoretical model suggested that the W-33.3 at% Zr binary system tended to form solid solution first and then transform into amorphous. Furthermore, high resolution transmission electron microscopy observation revealed that grain refinement, lattice distortion and dislocation may play an important role in the process of solid solution expansion and amorphization. Finally, thermal stability tests suggested that the prepared super-saturated solid solution powder has shown good stability at 800 ℃ for 2 h, which provides more possibilities for the application of W-Zr metastable alloy powders. [Display omitted] • W-33.3 at% Zr super-saturated solid solution was prepared by mechanical alloying firstly. • W-Zr super-saturated solid solution powder is completely stable after holding at 800 ℃ for 2 h. • Phase evolution of W-Zr binary system was studied by thermodynamic calculation. [ABSTRACT FROM AUTHOR]

Tin selenide (SnSe), a layered material with low thermal conductivity high thermoelectric properties, has recently attracted a lot of attention in the field of thermoelectrics. Herein, Sn 1−x Mn x Se is prepared by single-step hydrothermal route and the effect of Mn on the TE properties of SnSe compound were investigated. The formation of orthorhombic crystal structure is confirmed by X-ray diffraction (XRD) pattern. High crystalline nature of the sample and nanoparticles formation is observed in high resolution transmission electron microscopy (HRTEM). Thermal conductivity is obtained in the temperature range from 303 K to 653 K. The effect of Mn substitution leads to low thermal conductivity of 0.204 W/mK at 653 K, due to the shortened phonon lifetime through the various scattering mechanisms. This result demonstrates that the introduction of Mn substitution in SnSe can effectively lift the thermoelectric performance of polycrystalline SnSe via reduced thermal conductivity. ● Mn substituted SnSe samples were synthesized by hydrothermal method followed by cold pressing densification technique. ● Formation of grain boundaries, dislocations and mass fluctuation scattering synergistically reduced the phonon life time. ● Reduced phonon life time resulting in ultra-low thermal conductivity of 0.204 W/mK at 653 K. [ABSTRACT FROM AUTHOR]

In this study, oriented nano-sheets generated during the growth of cobalt-rich Co–V and Co–Zn thin films induced a large anisotropy in the magnetic and transport properties. The regular nano-sheets were tilted 52–54 deg. with respect to the substrate plane, ≈ 3.0–4.0 nm thick, ≈ 30–100 nm wide, and ≈ 200–300 nm long, with an inter-sheet distance of ≈ 0.9–1.2 nm. In spite of the different microstructures of the two kinds of samples where the Co–V films were amorphous, whereas the Co–Zn films showed a growth of Zn nanocrystals, the oblique nano-sheet morphology conferred noticeable shape anisotropy to both specimens. This anisotropy resulted in an in-plane uniaxial magnetic anisotropy. The changes in the nano-morphology caused by thermal treatments, and hence in their anisotropic properties, were studied. While the Co–V samples retained or increased their magnetic and transport anisotropies, this anisotropic behavior vanished for the annealed Co–Zn films. High resolution transmission electron microscopy, HRTEM, including chemical analysis at the nano-scale, and the dependence of the anisotropic resistance on temperature allowed to establish the nature and the activation energy spectra of the atomic relaxation processes during heating. These processes displayed a single peak at 1.63 eV for the Co–V and two peaks at 1.67 and 2.0 eV for the Co–Zn. These spectra and their singularities were associated to the changes induced in the nano-morphology of the films by thermal treatments. The Co–V films retained their nano-sheet morphology almost up to 500 ºC; the Co–Zn films lost their nano-sheets at 290 ºC. The thermal stability exhibited by the Co–V films makes them useful for applications in ultra high frequency, optical, magnetostrictive and magneto-electric devices. [Display omitted] • Morphology of oblique nano-sheets generated in Co–V and Co–Zn thin film compounds. • The nano-sheets generated in-plane uniaxial magnetic and transport anisotropies. • Annealed Co–V increased the anisotropy due to the nano-sheets preservation at atomic activation energies of at least 2.2 eV • Annealed Co–Zn lost their anisotropic properties because of the loss of nano-sheets at atomic activation energy of 1.57 eV. [ABSTRACT FROM AUTHOR]

• Hard-soft SrFe 12 O 19 /(CoEu 0.02 Fe 1.98 O 4) x nanofiber composites were prepared via electrospinning technique. • XRD, SEM and TEM analyses revealed the coexistence of hard and soft phases. • The magnitudes of optical bandgap E g are in the range of 1.56–1.77 eV. • The degree of exchange-coupling between hard and soft phases is well achieved. SrFe 12 O 19 (SFO) nanofibers (NFs), CoEu 0.02 Fe 1.98 O 4 (CEFO) NFs, and hard-soft (H/S) SrFe 12 O 19 (SFO)/(CoEu 0.02 Fe 1.98 O 4) x (CEFO) (x = 1.0, 1.5, 2.0, 2.5) nanofiber composites (NFCs) were produced via electrospinning approach. The X-ray powder diffraction (XRD) patterns for the studied compositions confirmed the coexistence of characteristics peaks of both phases (Sr-M-type hexaferrite and cubic spinel ferrite) without any impurity. The lattice parameters 'a′ and 'c′ for hexagonal SFO and 'a′ for CEFO NFs are fluctuating with increasing the ratio of CEFO NFs. The surface of nanofibers showed fibers having some roughness and bumps. They are consisted of hexagonal particles belong to SFO mixed and fine cubic CEFO NFs. These observations were confirmed by SEM (Scanning electron microscopy) along with EDX (Energy dispersive X-ray) and HR-TEM (High resolution transmission electron microscopy). The fibers showed a non-uniform cross-section with diameter between 33 and 95 nm. Diffuse reflectance spectroscopic (DRS) investigations were performed on SrFe 12 O 19 NFs, on soft CoEu 0.02 Fe 1.98 O 4 NFs, and on H/S (SFO)/(CEFO) (x = 1.0, 1.5, 2.0, 2.5) NFCs. Tauc method provided the estimation of optical bandgap (E g) of each sample. The magnitudes for E g are in the range of 1.56–1.77 eV. The magnetic responses of all samples in external applied magnetic field (M-H) were recorded at ambient temperature (T = 300 K) and low temperature (T = 10 K). Diverse produced nanofiber composites do not display no kinks in the measured M-H curves at both temperatures. Moreover, a single intense peak was clearly observed in the curves of dM/dH vs. H. These results reflected that the degree of exchange-coupling between hard and soft phases is well achieved via the employment of the electrospinning technique. At ambient temperature, it was observed that the magnetization is improving while the coercivity is diminishing with the increase in H/S ratio. On the contrary, at T = 10 K, the rise of CoEu 0.02 Fe 1.98 O 4 content within diverse H/S NFCs provokes a slight decline in magnetization and a great enlargement in coercivity. The plausible reasons for such tendencies were discussed. [ABSTRACT FROM AUTHOR]

Rare earth group elements have gained the renewed interest in applications of energy storage and conversion. Apparently, supercapacitive performances of electrodes based on yttrium (Y+3) element are still left uncovered for exploration as energy storage device. In this study, the binder free yttrium hydroxide (Y(OH) 3) electrodes have been prepared through easy, economical and industry applicable successive ion layer adsorption and reaction (SILAR) method. The Y(OH) 3 has been deposited over the stainless steel (SS) substrate for 10 (Y_10), 20 (Y_20) and 30 (Y_30) SILAR cycles. The prepared electrodes have been characterized by using X‐ray diffraction (XRD), fourier‐transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM). The electrochemical performances of the prepared electrodes have been studied in presence of 1 M Na 2 SO 4 electrolyte. The Y_20 shows the superior electrochemical performance than others. The highest specific capacity of 237 C g−1 has been observed for Y_20 at 1 mA current rate along with good cycle stability. Thus, by observing our results, one can say that the prepared electrode has a great potential in area of energy harvesting, power back up, portable devices, etc. [Display omitted] • Binder free yttrium hydroxide (Y(OH) 3) electrodes have been prepared by SILAR deposition method. • A crystalline nature of deposited electrodes has been observed with mesoporous nanostructures. • The highest specific capacity of 237 C g−1 has been obtained at 1 mA current rate. • The EIS is used to reveal the electrode parameters and the lowest value of Rs is 1.06 Ω. [ABSTRACT FROM AUTHOR]

• The structural transformation of Y 2 O 3 during high-energy ball milling is investigated. • Complete phase transformation from cubic to monoclinic is achieved after 30 h of milling. • XRD and Rietveld refinement analysis for the quantification of phase fraction, crystallite size and strain. • Transformation mechanism confirmed by HRTEM and EELS analysis. • Transformation sequence is: Yc → Yc + Ym → Ym. • Monoclinic Y 2 O 3 is found to be much finer than its cubic allotrope. [Display omitted] In-depth understanding of the structural transformation mechanism in nanocrystalline yttria (Y 2 O 3) is crucial to design advanced materials satisfying a wide range of technical demands. Present study investigates the structural modification in cubic Y 2 O 3 nanopowders induced by high energy ball-milling as a function of milling duration. Y 2 O 3 nanopowder with an initial crystallite size of 25–50 nm was subjected to high energy ball milling (1000 rpm) for incremental time periods up to 30 h. X-ray diffraction (XRD) and Rietveld analysis were employed to study the phase evolution, crystallite size, and strain at every stages of milling. High Resolution Transmission Electron Microscopy (HR TEM) and Electron Energy Loss Spectroscopy (EELS) is utilized to realize the mechanisms involved in phase transformation. It is observed that as milling duration progresses, the cubic Y 2 O 3 gets refined and gradually transforms to the monoclinic phase. It is also apparent that at finer sizes, the monoclinic phase is preferred over the cubic one. The critical crystallite size for the monoclinic phase to stabilize is observed to be ~ 13 nm. Results show the complete structural modification after 30 h of milling duration. [ABSTRACT FROM AUTHOR]

• Gd-Y co-doped BiVO 4 photocatalysts were synthesized by a surfactant free hydrothermal technique. • Co-doping modified the morphology of the photocatalysts. • The co-doped BiVO 4 photocatalysts exhibited promising dye degradation efficiency and stability. • A possible photocatalytic mechanism is proposed to understand the rationale behind the improved properties. [Display omitted] The development of metal oxide photocatalysts with improved dye degradation efficiency under natural sunlight is in increasing demand due to their superior chemical stability and cost effectiveness. In this context, Gd and Y co-doped BiVO 4 having the nominal compositions Bi 0.92 Gd x Y y VO 4 (0.06 ≤ x ≤ 0.08; 0 ≤ y ≤ 0.02) have been synthesized via a surfactant free hydrothermal technique. The structural characterizations by X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy confirmed a monoclinic to tetragonal phase transition induced by co-doping in BiVO 4. High resolution transmission electron microscopy images revealed successful synthesis of Gd and Y co-doped BiVO 4 with a very good crystallinity. The steady-state photoluminescence spectroscopy analysis indicated significant suppression of charge carrier recombination in the co-doped samples. Under simulated sunlight, Bi 0.92 Gd 0.07 Y 0.01 VO 4 photocatalyst demonstrated 94% degradation of methylene blue dye (MB) within 90 min of irradiation time, which is about 4 times higher than that of pristine BiVO 4 photocatalyst. This superior photocatalytic performance may be attributed to the synergistic effect of nanorod like shape of the synthesized materials, negative surface charge, and enhanced charge career lifetime of the Bi 0.92 Gd 0.07 Y 0.01 VO 4 photocatalyst. [ABSTRACT FROM AUTHOR]

Highlights: [•] Lithium nitride samples were obtained in Li–N system at nitrogen pressure 1–10atm. [•] Lithium nitride subjected to decomposition gets converted into carbonate. [•] β-Modification was achieved at a pressure 500 times lower than that required. [•] Structures with smaller crystallite size are created as the N pressure increases. [•] N content in the formed nitride structures increases with pressure. [ABSTRACT FROM AUTHOR]

• The variables of temperature, pressure and crystal size were examined separately. • The lattice parameters in HT-XRD are affected by both temperature and size effects. • The lattice parameter of Y 2 O 3 in MgO is higher than pure Y 2 O 3 according to HT-XRD. • A non-monotonic lattice variation (NMLV) in Y 2 O 3 due to the nano-effect was shown. • The NMLV was modeled combining the surface tension effect and the Madelung model. Yttrium oxide (Y 2 O 3) is a ceramic material in use in various fields such as catalysis, thermal barrier coatings, dental ceramics, solid-state lasers, solid oxide fuel cells and etc. In nanoscale metal oxides, unlike metals, the dependence of the lattice parameter on the crystal size is in dispute. Y 2 O 3 and 5 vol% Y 2 O 3 in MgO powders were synthesized via the sol-gel technique. The latter was made in order to produce Y 2 O 3 inclusions in MgO, allowing for the study of differences resulting from crystal size with inhibited thermal growth. However, the lattice parameters of the C-type Y 2 O 3 were significantly lower than expected due to misfit high compression stress. High-temperature X-ray diffraction (HT-XRD) was used in order to investigate in situ crystal structure and microstructure variations of Y 2 O 3 imbedded in MgO as formed at high temperatures free of misfit strain, comparing with in situ study of pure Y 2 O 3 formation at the same temperature range. It was found that nanocrystalline C-type Y 2 O 3 was formed at a temperature range of 873–1163 K. Lattice parameters and crystal size were evaluated by using Rietveld refinement and high resolution scanning electron microscopy (HR-SEM). The relative lattice parameter changes as a function of crystal size were obtained by analyzing the in situ HT-XRD data from 873 to 1573 K. Those results along with those obtained at room temperature showed a non-monotonic trend: lattice contraction versus decreasing crystal size at the range of 60–45 nm crystal size and lattice expansion versus decreasing crystal size for smaller crystals (approximately 0.11%). The non-monotonic lattice variation was modeled by assuming two effects acting simultaneously as a function of crystal size: lattice contraction due to hydrostatic pressure caused by the surface tension and Madelung model predicting lattice expansion due to weakening of bonding force in small ionic crystals. The calculated theoretical lattice parameters values which were obtained by using this model were compared to the experimental results yielding a better understanding of the lattice variations in nano-Y 2 O 3. [ABSTRACT FROM AUTHOR]

As a widely used water-soluble azo dye, methyl blue has aroused widespread concern for its environmental problems. In this paper, magnetic nickel-magnesium ferrites were deemed as a promising dye adsorbent, and they could be synthesized through a rapid combustion process. The properties of the nanoparticles were acquired by the scanning electron microscope (SEM), the energy dispersive spectroscopy (EDS), the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), the high resolution transmission electron microscopy (HRTEM), the N 2 adsorption-desorption isotherms, and the Fourier transform infrared spectroscopy (FTIR). The structure analysis demonstrated that the average particle size of magnetic nickel-magnesium ferrites was 59.2 nm, the saturation magnetization was 34.1 A·m2/kg and the specific surface area was 94.69 m2/g. After investigating the ratio of nickel to magnesium and the key parameters affecting the properties of ferrites, the adsorption of methyl blue onto the nanoparticles was discussed. Adsorption kinetics and isotherm models were employed to fit the relevant data, and the adsorption capacity of nanoparticles on methyl blue reached 306.4 mg/g when the initial concentration of methyl blue was 900 mg/L. The effect of pH value on the adsorption was explored, and seven cycles of the sample were recorded. Subsequently, the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS) curves of the nanoparticles before and after adsorption were measured. To sum up, nickel-magnesium ferrites had the advantages of low cost, magnetic separation, facile preparation, high adsorption efficiency, and reusability, which suggested it had a broad application prospect in the field of dye removal. Magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles are prepared via a rapid combustion process, the experimental data of methyl blue onto Ni x Mg (1−x) Fe 2 O 4 nanoparticles are described by the pseudo-second-order adsorption kinetics and Langmuir adsorption isotherm model at room temperature, and the adsorption mechanism is discussed. Besides, the electrochemical performance of methyl blue onto magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles before and after adsorption is analyzed by CV and EIS. [Display omitted] • Magnetic Ni x Mg (1−x) Fe 2 O 4 nanoparticles are prepared via a rapid-combustion process. • Adsorption mechanism of methyl blue onto Ni 0.9 Mg 0.1 Fe 2 O 4 nanoparticles is investigated. • Electrochemical performance of methyl blue onto nanoparticles is analyzed by CV and EIS. [ABSTRACT FROM AUTHOR]

• Graphene-Oxide(GO) modified NCM with oxygen vacancy layer is formed. • Modification mechanism in sintering process is keenly studied by Raman spectra. • GO-modified NCM exhibits enhanced electrochemical performances at high rates. • Li-ion diffusion coefficient in the charging / discharging process is tested by GITT. • Theory of phase transformation is further expounded via XRD and HRTEM. [Display omitted] The well-distributed smaller sized Graphene-Oxide-treated LiNi 0.5 Co 0.2 Mn 0.3 O 2 (GO-treated NCM) layered cathodes are successfully synthesized by hydrothermal method, which has truncated octahedral shape with evenly oxygen vacancy layer on the surface. With temperature ascends progressively, the cathode molding and the modification mechanism of Graphene-Oxide (GO) in the calcination process are keenly studied by Raman spectra. In addition, the synergistic effect of oxygen vacancy and cathode electrolyte interphase (CEI) layer at outer surface accelerates lithium diffusion coefficient during cycling. Especially, GO-treated NCM exhibits the optimal capacity retention as high as 78.8% after 150 cycles at 15 C, compared with NCM whose is only 38.4%. Even at full cell state, GO-treated NCM has better rate performance and displays excellent energy density as high as 310.5 Wh kg−1 after 200 cycles at 1 C (1 C = 160 mAh g−1). Ultimately, the theory of phase transformation of cycled cathodes is expounded in detail in combination with high resolution transmission electron microscopy (HRTEM) and the variation of X-ray diffraction (XRD) peaks positions. [ABSTRACT FROM AUTHOR]

Abstract: In this investigation the Al64Cu24Fe12 alloy was melted in an induction furnace and solidified under normal casting conditions. In order to obtain the icosahedral phase (i-phase) in a single-phase region, the as-cast sample was subject to a heat treatment at 700°C under argon atmosphere. Subsequently, the i-phase was milled for different times in order to evaluate phase stability under heavy deformation. X-ray diffraction (XRD) and high-resolution electron microscopy (HREM) analysis were conducted to the structural characterization of ball-milled powders. XRD results indicated a reduction in quasicrystal size during mechanical ball milling to about 30h. HREM analysis revealed the presence of aperiodic nano-domains, for example, with apparent fivefold symmetry axis. Therefore, the i-phase remains stable over the first 30h of ball-milling time. However, among 30–50h of mechanical milling the i-phase transforms progressively into β-cubic phase. [Copyright &y& Elsevier]

Abstract: In order to improve the hydrogen storage characteristics of the Mg2Ni-type alloys, Ni in the alloy is partially substituted by element Mn, and melt-spinning technology is used for the preparation of the Mg2Ni1−x Mn x (x =0, 0.1, 0.2, 0.3, 0.4) hydrogen storage alloys. The microstructures of the as-cast and spun alloys are characterized by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics of the alloys are measured by an automatically controlled Sieverts apparatus. The electrochemical performances are tested by an automatic galvanostatic system. The results show that the as-spun Mn-free alloy holds typical nanocrystalline structure, whereas the as-spun alloys containing Mn displays a nanocrystalline and amorphous structure. The hydrogen absorption and desorption capacities and kinetics of the alloys increase with rising spinning rate. Additionally, melt spinning markedly improves the electrochemical hydrogen storage capacity and cycle stability of the alloys containing Mn. With an increase in the spinning rate from 0 (As-casts is defined as spinning rate of 0m/s) to 30m/s, the discharge capacity of the (x =0.3) alloy mounts up from 92.3 to 211.1mAh/g, and its capacity retaining rate at 20th charging and discharging cycle grows from 36.21% to 76.02%. [Copyright &y& Elsevier]

Abstract: High-resolution electron microscopy (HREM) images of the overlap structures in TiAl have been studied by the comparisons of experimental techniques and theoretic simulations. Several misunderstandings about TiAl microstructures were corrected. First, studies revealed that the reported 9R structures in TiAl must result from the overlap of two twin-related γ laths. They were not the true 9R structure. Second, the fringes (FR) between the γ and α2 phases have once been misconsidered as the stacking faults fringes which promoted the α2 ↔γ phase transformations. This work proved them to be the fringes caused by the overlap of the α2 and γ phases. Through study of the imaging of the overlap structures, a new formation mechanism of the fringes has been proposed. [Copyright &y& Elsevier]

The initial stage processes of nucleation and growth of crystalline phases in Co-based amorphous microwires in a glass shell were studied by processing kinetic curves using various theoretical models. The results of X-ray diffraction for research of the microstructure evolution at Synchrotron Radiation Source and High Resolution Transmission Electron Microscopy were considered. The study of the crystallization process kinetics was carried out by a non-conventional method, in particular based on data of sample magnetization changes over time and with temperature at a unique in situ vibromagnetometer. The analysis of the kinetic curves for isothermal and non-isothermal crystallization process led to the similar conclusions and made it possible to establish the values of the Avrami exponent for the initial stage of surface and bulk crystallization, to establish the dimensionality of crystal growth, and to conclude that there was no nucleation in the process of crystal growth. Based on the analysis of kinetic curves by three methods, the activation energy of the primary crystallization process was determined, its high value is associated with the presence of chromium in the alloy, which determines its nanocrystallization. The microstructure and shape of crystals were analyzed. [Display omitted] • Kinetics of isothermal and non-isothermal crystallization was investigated by analysing of magnetization changes. • The study of phase transformations was carried out using synchrotron radiation and high-resolution electron microscopy. • The joint study of kinetics using JMAYK theory and structural changes was used to analyze crystallization mechanisms. • The mechanisms of surface and bulk nucleation and growth of crystals in an amorphous matrix have been established. • The activation energy of the crystallization process is established and the role of chromium in its increase is discussed. [ABSTRACT FROM AUTHOR]

Abstract: We have examined the structure of a Cu3Au-type compound CeRh3B0.5 by means of electron diffraction and high-resolution electron microscopy. The observed electron diffraction patterns of CeRh3B0.5 show the appearance of 1/21/21/2-type superlattice reflections and fine satellite reflections around all reflections. These features have not been detected by X-ray powder diffraction study. The new ordered structure producing the superlattice reflections belongs to a tetragonal system, space group I4/mmm (No. 139) and cell parameters of and c t =2c c =0.8196nm. The proposed model is characterized by ordering of both B atoms and Rh octahedrons. The observed high-resolution image taken with a diffraction pattern showing the satellite reflections along the [011] direction shows a domain structure with size of about 3nm, and a lattice modulation and some edge dislocations have been observed at boundaries between the domains. It is suggested that the anomalous behavior of hardness in CeRh3B x is caused by the appearance of this modulated structure. [Copyright &y& Elsevier]

Abstract: The controlled nanocrystallization of Nd–Fe–Co–Al–B bulk amorphous tunes the coercivity, which is enhanced to 23kOe, with a Curie temperature of 692K. Ferromagnetic Nd2(Fe,Co,Al)14B nanocrystallites isolated by amorphous clusters coexist with antiferromagnetic Nd6(Fe,Co,Al)14. These magnetic properties are examined by the combination of X-ray diffraction, high-resolution transmission electron microscopy, magnetization measurements, and Mossbauer spectrometry. The grain size for optimal magnetic properties is around 40nm. [Copyright &y& Elsevier]

The aim of the work is to present a comparative analysis (structural and magnetic) of Fe-C nanocomposites obtained by the thermal decomposition of sugars (fructose, glucose and sucrose) employing FeCl 3 as Fe3+ precursor. The thermal decomposition was followed through Thermogravimetry (TGA) and Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, High Resolution Transmission Electron Microscopy (HRTEM) and Raman spectroscopy. The results indicate the reduction of Fe3+ under the performed thermal treatments and the achievement at high annealing temperatures of Fe-C nanostructures (coexistence of α-Fe and Fe 3 C nanoparticles surrounded by a carbon matrix). The magnetic characterization performed by dc SQUID magnetometry, shows an antiferromagnetic response in the initial stages of the decomposition process, and a ferromagnetic behavior linked to the Fe-based nanoparticles. The magnetic induction heating was analyzed through the ac hysteresis loops. Moderate Specific Absorption Rate (SAR) is obtained in Fe-C nanoparticles (~ 70 W/g Fe), ascribed to the large nanoparticle size. The combination of porous carbon structure and ferromagnetic response of the Fe-C nanoparticles (i.e. local temperature increase under ac magnetic field) enlarge the emerging applications of these carbonaceous nanocomposites. • Fe-based carbonaceous nanocomposites obtained by thermal decomposition of sugars. • Fe 3 C and α-Fe nanoparticles encapsulated in a partially ordered carbon matrix. • Antiferromagnetic response characterizes the initial decomposition states. • Local temperature increase under ac magnetic field (moderate SAR values). [ABSTRACT FROM AUTHOR]

• We irradiated the La 2 Zr 2 O 7 pyrochlore using 1 MeV Xe4+ ions at ~ 88 K and 300 K. • Damage increases with ion fluence at both temperatures and is significantly higher at ~88 K compared to 300 K. • Lattice strain increases with enhanced fluence which bolsters the structural disorder phenomenon. • The variation in damage/amorphization and lattice strain is directly related to the change in the irradiation temperature and ion fluence. Evaluation of loss of crystallinity (damage/amorphization) of irradiated La 2 Zr 2 O 7 (1 MeV Xe4+ with fluence of 1 × 1013, 5 × 1013, and 1 × 1014 ions/cm2) at two different temperatures, i.e. , ~88 K and 300 K. ga1 State of the art applications (nuclear waste host, scintillators, piezoelectric, SOFCs, etc.) of isometric pyrochlore, A 2 B 2 O 7 , are very sensitive to the structural assessment upon ion irradiation. In the present study, La 2 Zr 2 O 7 is irradiated using 1 MeV Xe4+ ions with fluence of 1 × 1013, 5 × 1013, and 1 × 1014 ions/cm2 at ~ 88 K and 300 K. The impact of irradiation temperature and ion fluence on the structural properties of the La 2 Zr 2 O 7 are investigated using the GIXRD, Raman spectroscopy and high resolution transmission electron microscopy (HR-TEM). The GIXRD and Raman results indicate that the degradation of the crystallinity (i.e., damage/amorphization) are significantly higher with enhanced fluence at ~ 88 K than that of 300 K. The induced lattice strain also increases with an increase of ion fluence and it is more pronounced at ~88 K. The HR-TEM results of the La 2 Zr 2 O 7 samples exhibit that degradation of the atomic ordering are more pronounced at ~ 88 K. The prominent induced strain and degradation of crystallinity (i.e., damage/amorphization) at ~ 88 K appear to be ion fluence and irradiation temperature-dependent. This study is enlightening the effect of the ion fluence and irradiation temperature on the degradation of crystallinity (i.e., damage/amorphization). [ABSTRACT FROM AUTHOR]

Nanosecond laser pulses were used to synthesize Cu/CuO/Fe 3 O 4 and Al 2 O 3 nanocomposites by ablating Al–Cu–Fe quasicrystal (QC) in two different solvents, namely ethanol and deionized water. The ablation was performed for 15 min with two different laser fluences of 40 J/cm2 and 80 J/cm2 in both the media. The effects of these solvents have been studied to understand the structural and morphological transformations of nanoparticles using microscopic and spectroscopic techniques. X-ray diffraction (XRD), selected area electron diffraction (SAED) and Raman spectroscopy studies revealed the formation of Cu/CuO/Fe 3 O 4 and Al 2 O 3 nanocomposites in both the solvents. Furthermore, transmission elctron microscopy/high resolution transmission electron microscopy (TEM/HRTEM) and field emission scanning electron microscopy (FESEM) in combination with the energy dispersive X-ray mapping established the formation of NPs with a typical core-void-shell structure evolved in presence of ethanol, showing the crystalline Cu–Fe phase in the core and amorphous Al 2 O 3 phase in the shell. However, in the case of deionized water, the hollow structured NPs were obtained consisting of oxides of Cu, Fe and Al. The mechanisms of the formation of two structures in these two media are controlled by the Kirkendall diffusion process, which appears to be dependent on the physical properties of the solvent i.e., thermal conductivity, viscosity and, polarity. Based on the experimental observation, a possible mechanism for the observed morphology is discussed. Image 1 • Dealloying of Al–Cu–Fe quasicrystal materials by laser ablation. • By dealloying, Cu/CuO/Fe 3 O 4 and Al 2 O 3 nanocomposites were synthesized. • In ethanol, core-void shell structured nanoparticles were obtained. • In water, hollow nanoparticles were obtained composed of oxides of Al, Cu and Fe. [ABSTRACT FROM AUTHOR]

The γ" phase and the γ′ phase are metastable precipitates in Cu-2.0 wt%Be alloy, which play a key role in strengthening the alloy. This paper mainly discusses the formation process, microstructure and strengthening mechanism of these two precipitates. The structure, quantity and size of precipitates in the alloy treated at different aging temperatures were analyzed by transmission electron microscopy (TEM). The strengthening mechanism of the γ" phase and the γ′ phase was analyzed by theoretical calculation. The results show that with the increase of aging temperature, the size of γ" phase changes slightly, but the density decreases significantly, while the size and density of γ′ phase increase with the increase of aging temperature. High resolution transmission electron microscopy (HRTEM) analysis shows that the γ" phase is semi coherent with the matrix, so it will be cut off by dislocations. The atoms in the γ′ phase are arranged perfectly, they can't shear with dislocations, so they can be strengthened by the Orowan dislocation bypass mechanism. The strength mechanism of γ" phase is location shear mechanism and the strengthening mechanism of γ′ phase is Orowan bypass mechanism. • The evolution of metastable precipitates in Cu-2.0 wt%Be alloy was studied. • Both dislocation shear mechanism and dislocation bypass mechanism exist in Cu be alloy. • γ" phase strengthen alloy mainly through the shear mechanism, γ′ phase strengthen alloy mainly through the Orowan mechanism. [ABSTRACT FROM AUTHOR]

Hydrogen embrittlement is one of the most crucial problems in the application of advanced high strength steel (AHSS) sheets for the automotive industry. Especially, the severe plastic deformation in punched edges makes the components susceptible to hydrogen assisted cracking (HAC). While small amounts of hydrogen are measured in the bulk material, hydrogen concentration increases in the micrometer-sized shear affected zone many times, along with severe plastic deformation. To contribute to the understanding of local microstructure and local stress states on the hydrogen accumulation in the shear affected zone, two industrial AHSS were investigated. Both steels had the same ultimate tensile strength of 1200 MPa, but different uniform elongations. High-pressure torsion (HPT) deformed samples were used to represent the material state in the shear affected zone. Thermal desorption spectroscopy (TDS), X-ray diffraction (XRD), magnetic retained austenite measurements and electron backscattering diffraction (EBSD) in a high resolution secondary electron microscopy (SEM) were applied among other techniques to gain more insights with microstructural resolution. The hydrogen analysis results of the HPT samples were correlated with the local hydrogen trapping capacity in punched edges. Finally, a simplified "two-zone" model considering the bulk and punched edge as separate zones was developed in order to estimate the local hydrogen concentration of punched AHSS sheets as a function of hydrogen bulk concentration. In a concluding remark it is shown, that the effect of the hydrostatic stress field as trap site is negligibly small compared to other traps. • Role of microstructure and plastic deformation on hydrogen trapping is investigated. • A heat treatment at 150 °C decreases hydrogen uptake from electrochemical sources. • Hydrogen analysis- and model-based evaluation provides hydrogen localization. • Punched edges exhibit a by a factor of 5–10 increased local hydrogen concentration. • Volume residual stresses have a negligible effect on hydrogen accumulation. [ABSTRACT FROM AUTHOR]

Fe 64 B 24 Y 4 Nb 6 metallic glass ribbon and its bulk counterpart were characterized by conventional and high rate differential scanning calorimetry, electron probe microanalysis, in-situ X-ray diffractometry, high resolution transmission electron microscopy and instrumented microhardness. The metallic glass possesses a high glass forming ability. It is thermally stable up to 585 °C while primary crystallization of Fe 2 B and FeB occurs at 677 °C. Estimated by the Kissinger and Moynihan's methods, the activation energy of glass transition was shown to be lower than that of primary crystallization. After total crystallization, the bulk alloy contains a terminal Fe solid solution, Fe 2 B, FeB, Fe 3 B 8 Nb 7 and BFe 14 Y 2 phases while the ribbon contains additional yttria as well. The loading and unloading curves as well as the indentation features are very suitable in order to evidence the effect of the various crystallization events on the mechanical behavior of the bulk alloy. The hardness of the amorphous and fully crystallized bulk alloys amount to 1198 ± 21 and 461 ± 65 HV 0.5 , respectively and their reduced Young modulus are close to 174 ± 5 GPa. The deformation ability of the fully crystallized alloy is twice that of the glassy alloy. • The Fe 64 B 24 Y 4 Nb 6 metallic glass presents a high glass forming ability. • Its supercooled domain extends over a 80 °C range. • The primary crystals are FeB and Fe 2 B. • The fully crystallized alloy contains a Fe solid solution, Fe 2 B, FeB, Fe 3 B 8 Nb 7 and BFe 14 Y 2. • The mechanical behavior changes noticeably with the crystallization progress. [ABSTRACT FROM AUTHOR]

In the present work, the influence of trace level Cu on intergranular corrosion (IGC) in AA6082 Al–Mg–Si alloy is studied using correlative accelerated corrosion testing and high resolution electron microscopy. Further, grain boundary structure and its correlation to IGC are also investigated using electron backscatter diffraction (EBSD) and transmission Kikuchi diffraction (TKD). It is found that in AA6082-T6 alloy with very low Cu content (0.06 wt%), about 13% of high angle grain boundaries have Al 2 Cu precipitates, which promotes IGC at the grain boundaries. • In AA6082-T6 alloy with 0.06 wt % Cu, Al 2 Cu precipitates are present at 13% of high angle grain boundaries. • Low angle grain boundaries in the AA6082-T6 alloy are almost free of precipitates. • The presence of Al 2 Cu precipitates at high angle grain boundaries increases susceptibility to IGC in acidified NaCl solution. • Low angle grain boundaries show low susceptibility to intergranular corrosion in acidified NaCl solution. [ABSTRACT FROM AUTHOR]

Electrochemical sensing of 4-acetaminophen by nickel oxide modified glassy carbon electrode was explored. Nickel oxide was prepared through simple hydrothermal method. The physical characterizations of nickel oxide nanoparticle were carried out by using advanced characterization techniques to investigate the phase transformation, surface morphology and functional groups present in the nickel oxide nanoparticle. Characterization techniques such as X-ray diffraction spectroscopy, ultra violet-visible spectroscopy, Fourier transform infra-red spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy and high resolution transmission electron spectroscopy were used. Particularly, high resolution transmission electron microscopy studies revealed particle size in the range of 15–20 nm. Herein, we report nickel oxide modified electrode for the detection of 4-acetaminophen under neutral condition using phosphate buffer solution (pH = 7). The nickel oxide modified electrode was used to detect 4-acetaminophen by cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques. The oxidation peak potential of 4-acetaminophen was observed at 0.35 V. The sensitivity and limit of detection for the determination of 4-acetaminophen were 91.0 μA cm−2 mM−1 and 0.23 μM, respectively. The sensor also demonstrates wide detection range (7.5–3000 μM), good stability, selectivity and antifouling properties. The practical applicability of the proposed sensor was successfully demonstrated for the determination of 4-acetaminophen in different human serum real samples and paracetamol tablets. Image 1 • Well-crystalline NiO nanoparticles prepared by a facile hydrothermal method. • Electrochemical sensing of 4-acetaminophen was evaluated using the NiO modified electrode. • Cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques were used for the detection of 4-acetaminophen. • The sensitivity and limit of detection were found to be 91.0 μA cm−2 mM−1 and 0.23 μM, respectively. [ABSTRACT FROM AUTHOR]

A series of mixed-phases TiO 2 is fabricated via a mild hydrothermal process using titanium trichloride as the Ti source and ammonia water for regulating the ratio of anatase, rutile, and brookite. As a result, TiO 2 nanocrystals comprised of anatase/brookite, anatase/rutile/brookite and anatase/rutile phases can be obtained. The longest optical edge is observed for triphase TiO 2 system among all of the as-prepared samples in UV–vis absorption spectroscopy. However, the results for the photodegradation of levofloxacin indicate that the diphase TiO 2 (A 61 B 39) shows higher degradation ratio of levofloxacin instead of triphase TiO 2. The reasons for these are attributed to the lowest recombination rate of photoinduced charges, the most negative of flat potential, and the larger specific surface area (S BET = 101 m2/g) for A 61 B 39 sample, which are demonstrated by photoluminescence spectra, Mott-Schottky plots, and N 2 adsorption-desorption isotherms. Besides, the intimate interfacial structure of different phase can be observed from high resolution transmission electron microscopy, which contributes to charge transfer. Meanwhile, the photodegradation mechanism of levofloxacin over A 61 B 39 is expounded. This work demonstrates a facile method to regulate the phase ratio of TiO 2 and facilitate its application in environmental remediation. TiO 2 nanocrystals with tunable anatase/rutile/brookite phase ratios were synthesized by a hydrothermal reaction of TiCl 3 with different concentration of NH 3 ·H 2 O and photocatalytic degradation of antibiotic levofloxacin was investigated. Image 1 • Mixed-phase TiO 2 nanocrystals are obtained via hydrothermal treatment of TiCl 3 and NH 3· H 2 O. • The tunable phase ratio of TiO 2 is achieved by changing the added concentration of NH 3 ·H 2 O. • The intimate interfacial structure of different phase contributes to photoinduced charge transfer. • Biphasic TiO 2 (A 61 B 39) shows the highest photodegradation activity of levofloxacin. • High photocatalytic properties are results of multiple factors together rather than single factor. [ABSTRACT FROM AUTHOR]

In ultra-high strength Al-Zn-Mg-Cu alloys, traditional heat treatments such as peak aging, two-stage aging and retrogression and re-aging cannot perfectly balance the relationship between mechanical properties and corrosion resistance and usually consume more time. Based on previous studies, the aim of this paper is to establish a suitable non-isothermal aging method for ultra-high strength Al-Zn-Mg-Cu alloys. In this study, after enhanced solution treatment and aging process with the heating rate of 20 °C/h, the alloy achieves excellent hardness and ultimate tensile strength of 195.7 HV and 680 MPA, respectively. When heating rate increases to 40 °C/h, non-isothermal aging can also ensure the alloy achieve the excellent mechanical properties (195.6 HV, 675 MPA). Similar to mechanical properties, the samples have outstanding resistance to intergranular and exfoliation corrosion, which is in accordance with the results of potentiodynamic polarization and electrochemical impedance spectroscopy tests. Evidences from high resolution transmission electron microscopy show that non-isothermal aging can promote the formation of a large number of smaller GP zones, η' precipitates and few η 2 precipitates inside grains, which greatly strengthens the mechanical properties. Furthermore, the grain boundaries precipitates transform from continuous to discontinuous and precipitate free zones form gradually, which greatly enhances the corrosion resistance. Because of these precipitates inside grains and grain boundaries, the samples with enhanced solution treatment +20 °C/h aging process and both solution treatments +40 °C/h aging process can achieve good mechanical properties closing to T6 state and corrosion resistance similar to T74 state simultaneously with much less aging time. Image 1 • The non-isothermal aging was designed as a novel route for heat treatments of ultra-high strength Al-Zn-Mg-Cu alloy. • An excellent combination of strength-ductility and corrosion resistance was achieved in the studied alloy. • The strengthening and corrosion mechanisms of non-isothermal aging on the studied alloy were discussed systematically. • Precipitation behavior of MgZn 2 strengthening phase was well studied. [ABSTRACT FROM AUTHOR]

Major challenges in casting routes for the fabrication of metal matrix nanocomposites are the weak bonding between reinforcement and matrix, porosity and nonuniform distribution of nanoparticles in the matrix alloy following in the presence of agglomerated nanoparticles and reinforcing nanoparticle free zones. Applying accumulative roll bonding as a severe plastic deformation process can improve the microstructure of the matrix alloy and the distribution of reinforcing nanoparticles in the metal matrix after the production of the casting nanocomposite. In this study, the accumulative roll bonding process was used to complete the composite fabrication process on the as cast AA2024-(SiO 2 +TiO 2) hybrid nanocomposites. The microstructural and mechanical examinations of the accumulative roll bonded hybrid nanocomposites were characterized by measurement of density using the Archimedean immersion method, optical metallography, field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and hardness and tensile tests. The results showed that the microstructure of the accumulative roll bonded hybrid nanocomposite had a great distribution of nanoparticles in the matrix without any significant porosity. In the final nanostructured hybrid nanocomposite, the grain size of 100 nm was obtained. Mechanical examinations also indicated that the hardness, ultimate tensile strength and yield stress of the nanocomposite increased as the number of accumulative roll bonding cycles increased. After five accumulative roll bonding cycles, hardness, ultimate tensile strength and yield stress values of the nanocomposite increased about 160%, 110% and 300% rather than those of non-accumulative roll bonded monolithic product, respectively. • In this study, AA2024-(SiO 2 +TiO 2) hybrid nanocomposites were fabricated by using ARB after stir casting method. • The results are discussed in terms of the effects of ARB process and the reinforcement addition on the obtained properties. • The effects of the ARB process on nanoparticle distribution and resulted mechanical properties were investigated. [ABSTRACT FROM AUTHOR]

In this paper, a Ti6Al4V-Mg3AlZn laminate metal composite (TC4-AZ31 LMC) was successfully prepared by hot pressing sintering. The interfacial microstructure of this composite was investigated using scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD) and high resolution transmission electron microscopy (HR-TEM). The three-point bending (TPB) tests of TC4-AZ31 LMC were performed to determine the foil-foil interface bonding properties. Results show that the AZ31 matrix of the TC4-AZ31 LMC possesses a strong {10-10} <0001> sheet texture and the adjacent AZ31 foils are bonded well through the migration of grain boundaries across the original boundaries of the foils. A continuous interfacial reaction layer consisting of an intermetallics layer, a nanocrystalline-amorphous mixture layer and a bulk-precipitated particles region was formed around the TC4/AZ31 interface. The intermetallics layer bordering on TC4 reinforcement was identified as Al 192.40 Fe 46.22 phase. The nanocrystalline-amorphous mixture layer was composed of MgO nanocrystalline and Mg-O amorphous phase. The bulk-precipitated particles locating at the boundary of AZ31 matrix were determined as complex precipitates containing Al 6 Mn and Al 13 Fe 4 phases. Compared with the AZ31 alloy, the TC4-AZ31 LMC possessed a superior bending strength, which is attributed to the effective load transfer capability from the AZ31 matrix to high strength TC4 reinforcement through the well-bonded TC4/AZ31 interface. • The interfaces of TC4-AZ31 LMC were studied by EBSD and TEM systematically. • The extremely thin intermetallics and nanocrystalline-amorphous reaction layers were formed along the TC4/AZ31 interface. • The grains of AZ31/AZ31 interface were bonded together by grain boundaries migration. • The composite showed superior bending properties than AZ31 alloy. [ABSTRACT FROM AUTHOR]