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Artificial Neural Networks (ANNs) have reshaped computing paradigms, transcending traditional methods. Leveraging oxide-based bilayer RRAM memristors, specifically TiO2/ZrO2 deposited via sputtering, offers remarkable potential for RS memory and neuromorphic computing. This study pioneers an extensive annealing approach to counteract variability challenges in LRS and HRS during endurance tests. The Pt/TiO 2 /ZrO 2 /Pt memristor device's structural aspects are validated through cross-sectional high resolution transmission electron microscopy (HRTEM) analysis. Systematic XPS examination investigates the impact of annealing on oxygen vacancies. Successful bipolar resistive switching is unveiled through I-V characteristics, with 550°C annealing optimizing stable endurance cycling (1000 dc cycles). Conduction mechanisms during set/reset are illuminated, corroborated by Schottky emission fitting. Synaptic behavior emulation, Spike-Timing-Dependent Plasticity (STDP), and theoretical simulations with a 28×28 MNIST dataset underscore the ANN's 84.6% average recognition rate. The amalgamation of MNIST-based artificial learning and the innovative annealing strategy holds exciting potential for memory applications and advanced neuromorphic explorations. • Enhanced synaptic behavior in ZrO 2 /TiO 2 memristive synapses via extensive annealing strategy. • Annealing impact on oxygen vacancies assessed by XPS, improving electrical properties. • Optimal 550°C annealing ensures stable endurance cycling, minimal resistance state variations. • Long-term synaptic traits emulated via weight updates using matching pulse sequences. • ANN using 28×28 MNIST data attains 84.6% average recognition rate. [ABSTRACT FROM AUTHOR]

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]

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]

• 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]