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The deformation behavior including flow behavior, hot workability and dynamic recrystallization (DRX) mechanism of as-cast Mg-9Gd-3Y-3.75Zn-0.6Zr alloy containing 26.5 % volume fraction 18R long-period stacking ordered (LPSO) phase distributed in continuous network morphology were studied by hot compression experiments at deformation condition of 350 ℃-500 ℃, 0.01–1 s−1 strain rate and 0.75 true strain. The influence of deformation conditions on the microstructural evolution was analyzed by using optical microscopy (OM), scanning electron microscope (SEM), electron back scatter diffraction (EBSD) and transmission electron microscope (TEM). Results display that stress exponent and deformation activation energy are 5.58 and 241.39 kJ·mol−1 correspondingly, which suggested that dislocation climb is the principal deformation mechanism. The Arrhenius type constitutive equation is established as ε ̇ = 4.09 × 1 0 16 sinh (9.922 × 1 0 − 3 σ) 5.58 exp (− 241394 RT). Microstructure evolution can be characterized by Zener-Holomon parameter (Z) which reflects the combining effect of temperature and strain rate on microstructure. At low lnZ (lnZ<36), the 18R-LPSO phase dissolves from continuous network to blocks and high DRX volume (>50 %) is realized by particle-stimulated nucleation and discontinuous dynamic recrystallization. At moderate lnZ (36≤lnZ<40), a fine and coarse grains bimodal structure is formed at the original grain boundary by continuous dynamic recrystallization resulting in a DRX volume between 10 % and 50 %. At high lnZ (lnZ≥40), layered 14H‐LPSO phase precipitates and inhibits DRX (DRX volume＜10 %) by absorbing dislocations. With combination of dissipation coefficient, instability factor and microstructure analysis, 400 ℃/0.01–0.05 s−1 and 450 ℃/0.01 s−1 are confirmed as optimal hot working domains for the as-cast alloy, under which conditions bimodal microstructure and equiaxed grains microstructure (average grain size 10.3 μ m) can be formed correspondingly. • The microstructure can be customized according to Zener-Holloman value. • DRV dominates with 40≤lnZ<46 and DRX dominates when 32≤lnZ<40. • Precipitation of 14H‐LPSO in grains is a coupling result of temperature and compressed loading. • The intragranular 14H-LPSO leads to a high activation energy Q and restricts the DRX. [ABSTRACT FROM AUTHOR]

In this article, the effect of CaTiO 3 on the structural and microwave dielectric characteristics of MgTiO 3 has been discussed. The (1-x)MgTiO 3 - xCaTiO 3 (abbreviated as (1-x)MT- xCT) for x = 0.025, 0.05, 0.075, 0.1 ceramics have been developed using a solid-state reaction route. The structural as well as morphological characteristics of specimens have been observed by employing X-ray diffraction and scanning electron microscope methods. The Rietveld refinement technique of X-ray diffraction data have been conducted for the refinement of structural phases. It suggests that two crystallographic phases have been present in all materials. The SEM images display dense well-identified grains of (1-x)MT - xCT (for x = 0.025–0.1) ceramics. The Raman spectroscopy method has been employed to detect the symmetry of ceramics and modes of vibration of the materials. The microwave dielectric characteristics like dielectric permittivity (ε r), loss (tanδ), quality factor (Q×f), and temperature coefficient at resonant frequency (τ f) of (1-x)MT - xCT (for x = 0.025–0.1) ceramics have been thoroughly investigated. The bond strength, bond valency, bond energy, and tolerance factor of (1-x)MT - xCT (for x = 0.025–0.1) materials have been evaluated and their relation with microwave dielectric characteristics has been discussed. The (1-x)MT - xCT (for x = 0.025–0.1) ceramics show excellent dielectric properties with near to zero τ f. In addition, DRAs have been designed with (1-x)MT - xCT (for x = 0.025–0.1) materials as dielectric resonators and various antenna properties have been studied with the help of HFSS software. This work suggests that (1-x)MT - xCT for (x=0.05) material can be a promising candidate for DRA applications working in the C band. • Structural study of (1-x)MgTiO3-xCaTiO3 ceramic is carried out using XRD, SEM, Raman and Rietveld refinement Technique. • The microwave dielectric characteristics such as Ɛ r , loss, Q f , and τ f have been thoroughly investigated. • The bond strength, valency, energy, and tolerance factor have been correlated with microwave dielectric characteristics. • DRAs have been designed and various antenna properties have been studied with the help of HFSS software. [ABSTRACT FROM AUTHOR]

The La 0.8- x Pr x Mg 0.2 Ni 3.8 (x = 0, 0.05, 0.1, 0.2, 0.3) alloy were synthesized useing the induction melting method. X-ray diffraction, scanning electron microscope, electron probe micro analyzer, and electrochemical tests were used to analyze the structure and electrochemical performance of the La 0.8- x Pr x Mg 0.2 Ni 3.8 (x = 0–0.3) alloy. It was studied how the Pr element affected the electrochemical characteristics and microstructure of the A 5 B 19 La-Mg-Ni based hydrogen storage alloy. The results show that the alloy consists of the CaCu 5 -LaNi 5 phase, 2 H-Pr 5 Co 19 phase, and 3R-Ce 5 Co 19 phase. The abundance of the A 5 B 19 phase increase with the increase of Pr content, while the abundance of the LaNi 5 phase decrease, and the addition of Pr promotes the formation of the 2 H-Pr 5 Co 19 phase. According to the results of the electrochemical test, every sample has good activation qualities, and the activation can be completed in 3–4 times. The activation properties are not significantly altered by the addition of Pr. The maximum discharge capacity increases at first, then decreases, reaching the highest 371.15 mAh g−1 at x = 0.2. The cyclic stability gradually improves with increasing content of Pr, and the maximum capacity retention rate reaches 85.80 % after 100 cycles. The primary factor influencing the alloy's high rate discharge ability is the exchange current density. With the increase of the exchange current density, the high rate discharge performance is gradually enhanced. • The La-Mg-Ni based hydrogen storage alloy A 5 B 19 has better performance than AB 3 and A 2 B 7. • The hydrogen storage alloy was partially substituted by Pr element with higher electronegativity. • The addition of Pr significantly improves the phase structure stability and cycle stability of the alloy. • The corrosion and oxidation of the alloy electrode during the cycle are improved. [ABSTRACT FROM AUTHOR]

Al-substituted strontium hexaferrite (SrFe 12– x Al x O 19 ; x ≤ 2.0) materials were synthesized using the hydrothermal technique. The influence of the Al3+ substitution has been examined using the powder X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Field-emission scanning electron microscope (FE-SEM), and the vibrating sample magnetometry (VSM). Hexagonal phase formation with P6 3 /mmc symmetry for all the compositions was confirmed by XRD study. With the increase of Al3+ concentration, lattice parameters gets contracted. Enhanced magnetic properties were observed in the Al-substituted strontium hexaferrite. The morphology of the undoped and doped samples were changed from irregular hexagonal flakes to plate-like (rod-like) shapes. In this study, the energy product (BH) max = 2.05 MGOe and squareness ratio (M r /M s) = 0.55 were obtained for an Al concentration of x = 1.5. The maximum value of the anisotropy constant (K eff) was 13.49×106 erg cm−3, for Al3+ doping content (x) = 1.5, which is tremendously high and possesses potential for its application as permanent magnets. [Display omitted] • Preparation of single domain SrFe 12-x Al x O 19 with x=0.0–2.0 using low temperature hydrothermal technique. • Determination of Saturation magnetization via Law of approach to Saturation. • Notable (BH) max of 2.045 MGOe is recorded for x=1.5 without any inclusion of rare-earth element. • Unprecedented anisotropy constant (13.49×105 J-m−3), magnetic hardness >1 and high squareness ratio (>0.54) suggests potential application in PMs. [ABSTRACT FROM AUTHOR]

Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 are two promising transparent ceramic materials with high density and effective atomic number. However, the phase diagram of Gd 2 O 3 -Sm 2 O 3 -ZrO 2 system has not been systematically studied. To determine the phase relationship of the ternary system Gd 2 O 3 -Sm 2 O 3 -ZrO 2 at 1600°C and 1400°C, a serious of ceramic samples were prepared and studied by X-ray diffraction, scanning electron microscope, and electron probe microanalysis. In the range of 66.6 mol.% ZrO 2 , the solubility of Gd 2 O 3 is 20–22.5 mol.% at 1600°C, and the binary intermediate phases Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 form a continuous solid solution at 1400°C. Using the experimental data as a foundation, thermodynamic modeling was performed using the approach. Based on the experimental data, the mixing parameters of fluorite, B and C phases were optimized, and thermodynamic modeling was performed using the CALPHAD (CALculation of PHAse Diagram) method. For the first time, a self-consistent database for Gd 2 O 3 -Sm 2 O 3 -ZrO 2 ternary system was established. • Phase equilibria of Gd 2 O 3 -Sm 2 O 3 -ZrO 2 system were studied experimentally at 1600°C and 1400°C. • At 1400°C, Gd 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 form a continuous solid solution, and at 1600°C, the solubility of Gd 2 O 3 is 20-22.5 mol%. • A set of self-consistent thermodynamic description for the Gd 2 O 3 -Sm 2 O 3 -ZrO 2 system was established for the first time. [ABSTRACT FROM AUTHOR]

The transition metal Manganese (Mn)-doped Zinc Oxide (ZnO) nanoparticles were synthesized using the sol-gel method. The nanomaterials ZnO and Zn 1-x Mn x O (x=0–0.15) formation, their crystal structure, and morphological properties were confirmed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analysis of the materials. All the studied materials show hexagonal wurtzite structure with the particle size in nanometres. The optical properties of transition metal Mn-doped ZnO nanomaterials were explored by the absorption and transmission spectra. The band gap of the nanomaterials decreases with the increase of Mn doping concentration from 3.01 to 3.26 eV. The mobility and electrical conductivity of the Mn-doped ZnO thin films show a decreasing trend with the increase of Mn doping concentration in ZnO. The Mn-doped materials were investigated for supercapacitor and photodiode applications. The Zn 0.90 Mn 0.10 O nanomaterials show the maximum specific capacitance, power and energy density of ∼ 220 F/g, 2202 W/kg and 1.15 Wh/kg, respectively. The electrochemical properties confirm that the doping of ZnO opens a new window for its application in energy storage devices. The ZnO and Mn-doped ZnO were used as an electron transport layer in perovskite MAPbI 3 photodiodes. Under the Illumination of blue (465 nm) light, the highest detectivity of undoped ZnO perovskite photodiode is ∼4.5×1010 Jones and doped ZnO perovskite photodiode is 0.7×1010 Jones, respectively. The low mobility of charges and unfavorable energy level alignment of Mn-doped ZnO with MAPbI 3 thin films is the reason for the decrease in photo detectivity. Our studies demonstrate that the Mn-doped ZnO nanomaterials and their thin films have avenues for potential application in energy storage devices and photodiodes of perovskite MAPbI 3. [Display omitted] • The hexagonal wurtzite crystal structure was achieved for Mn-doped ZnO nanomaterials. • The band gap has a decreasing trend with the increase of Mn doping concentration. • The highest specific capacitance for undoped ZnO, 0.05,0.10 and 0.15 of Mn-doped ZnO nanomaterials are 200, 185, 220, and 172 Fg−1, respectively. • The internal resistance, polarization and mechanical stress caused by the insertion and removal of ions from the electrode may be the reason of the decrease in specific capacitance. • The highest detectivity for MAPbI 3 thin film PDs A and B is ∼4.5×1010 jones and 0.7×1010 jones upon 5 mW/cm2 UV Illumination (635 nm) light at an applied bias of −4 V. [ABSTRACT FROM AUTHOR]

Metastable phase transformations of TiAl-based alloys provide a pathway for grain refinement and performance improvement. In this paper, the microstructure evolution of an as-extruded Ti-47Al-2Cr-0.2Mo alloy during quenching and tempering was investigated by scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM), and the mechanical properties of the alloy were further evaluated by tensile tests. The results indicated that the analogous Σ3 coincidence site lattice (CSL) and γ/γ true twin interface appeared in both the Widmanstätten structure (γ w) and feathery structure (γ f), implying that sympathetic nucleation mechanism was responsible for the nucleation of the metastable phases. A 6 H intermediate phase with the long period stacking ordered structure (LPSO) was discovered after short-term water quenching, which provided an evidence supplement of the sympathetic nucleation mechanism. The transformation path of the metastable γ w phase was proposed to follow the sequence of α/α 2 →6 H→γ. Apparent refinements of both grains and α 2 /γ lamellar colonies ((α 2 +γ) L) were exhibited after metastable phase transformation. The ultimate tensile strengths of the heat-treated alloy at whether room temperature (RT) or 800 °C were obviously improved, and the elongation at RT also kept at a considerable level. [Display omitted] • Sympathetic nucleation mechanism is responsible for the nucleation of γ w and γ f. • 6 H structure acts as an intermediate phase during metastable phase transformation. • γ f and γ w laths grow in "side-by-side" and "face-to-face" patterns, respectively. • Tensile strengths are obviously improved by metastable phase transformation. [ABSTRACT FROM AUTHOR]

In this work, using different manganese sources, Co-Mn-Fe-Zn-Ni-O high-entropy ceramics (HECs) were synthesized via the solid-phase method. X-ray diffraction (XRD) data showed that the HECs consist of rock salt and spinel phases, and the choice of raw materials has a great influence on the phase composition and lattice distortion of HECs. Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) analyses showed that the HECs have dense microstructures, with the major elements conforming to iso-atomic ratios. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy data showed that Mn3+ ions with Jahn-Teller effects distort the [MnO 6 ] octahedra, affecting the electrical properties and aging stability of the material. The room-temperature resistivity of the HEC systems ranged from 20.81 kΩ cm to 35.43 kΩ cm, and the B 25/50 resistivity values varied between 4037 K and 4048 K. The resistance drift was observed to be less than 0.70 % after aging at 125 °C for 1000 h. Impedance analyses suggested that the electrical properties of the high-entropy ceramics can be modulated by tailoring the grain size and grain boundary morphology. Selecting suitable raw materials based on valence-induced effects and the tendency of ions to occupy specific sites offers new insights into the design and synthesis of tailor-made high-entropy NTC ceramics. • Valence-induced of Mn oxides has a large impact on the electrical properties of HEC. • Design of high performance NTC ceramics based on cationic occupancy tendency. • Mn 3 O 4 feedstock initially contributes to spinel phase formation. • The resistance drift rates of Mn 2 O 3 -based HEC after aging for 1000 h are 0.61 %. • Customized high-performance NTC ceramics by selecting the different raw materials. [ABSTRACT FROM AUTHOR]

Failure and healing behavior of oxide scales for powder metallurgy superalloy with varying Nb contents (0, 0.5, 1, 2 wt%) during cyclic oxidation were studied. The cyclic oxidation test of four alloys was conducted using the discontinuous thermogravimetric method which consists of 100 cycles of 1 h exposure in air from 20 °C to 900 °C. The oxide scales after cyclic oxidation were systematically characterized by scanning electron microscope (SEM), laser scanning microscopy (LSM) etc. It has been found that the spallation of oxide scale in all alloys took place via expanding of the initiated cracks at grain boundaries into grain matrix. After spallation, the exposed alloy matrix would be re-oxidized into a Cr 2 O 3 layer to recover the failed oxide scales. The spallation tendency of oxide scale was significantly inhibited by Nb addition. This can be ascribed to the faster regeneration of Cr 2 O 3 layer in alloy with higher Nb content. • Nb addition significantly decreased the spallation of oxide scales. • The spallation in oxide scales starts in terms of cracks near grain boundaries. • The repetitive regeneration of Cr 2 O 3 of high-Nb alloy resulted in a smaller spallation area of the oxide scales. [ABSTRACT FROM AUTHOR]

(CoCrFeMnNi)90Al6Ti4 high entropy alloy (HEA) was prepared by adding Al and Ti elements into CoCrFeMnNi HEA. The alloy underwent processes including copper mold suction casting, 1473 K homogenization, 30 % cold rolling + 1273 K annealing + 1073 K aging, and water quenching and heating treatment. Microstructure and phase composition of both as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied using metallographic microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), and transmission electron microscope (TEM). The effect of heat treatment processes on the precipitation of second phases in (CoCrFeMnNi)90Al6Ti4 HEA was investigated, and mechanical properties of as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied via hardness tests. The results show that in as-cast (CoCrFeMnNi)90Al6Ti4 HEA, the second phase precipitated is primarily L21 structured AlTiNi2 phase. After homogenization, cold rolling, annealing, and aging processes, both the quantity and size of the second phase increase, with a small amount of nanoscale L12 phase appearing after aging treatment. With the progression of heat treatment, the hardness of (CoCrFeMnNi)90Al6Ti4 HEA increases, and mechanical properties are improved. • (CoCrFeMnNi)90Al6Ti4 high entropy alloy (HEA) was prepared by adding Al and Ti. • Microstructure and phase composition of (CoCrFeMnNi)90Al6Ti4 HEA were studied. • The second phase precipitated is primarily L21 structured AlTiNi2 phase. [ABSTRACT FROM AUTHOR]

The phase stability and quality of CsPbI 2 Br perovskite film directly determines the performance of perovskite solar cells (PSCs). However, there is a lack of research on phase stability of perovskite films of PSCs. Here, by simply controlling precursors with specified ratios and solvents, the phase stability, charge transfer resistance and electron lifetime improve significantly which is useful for high performance in perovskite solar cells. Besides this, the information about trap centres by a novel technique Charge Deep Level Transient Spectroscopy (Q-DLTS) also helps to improve efficiency of perovskite solar cells. In this work, CsPbI 2 Br perovskite thin films have been synthesized using simple solution processing method, by varying CsBr and PbI 2 precursors with specified ratios of 1.05 M:1 M and 1.10 M:1 M in Dimethysulfoxide (DMSO) and Dimethyl formamide (DMF). The CsPbI 2 Br film with ratio of 1.05:1 has more phase stability in ambient air at room temperature than that of 1.10:1. Drop casting method was adopted for thin films preparation and structurally cubic phase of perovskite films obtained by X-ray diffraction (XRD). Scanning electron microscope (SEM) showed more homogeneity on the surface of the sample with ratio 1.05:1 and energy dispersive x-ray spectroscopy (EDX) confirmed the presence of same amounts in chemical composition. Fourier transform infrared spectroscopy (FTIR) transmittance spectra showed that main peak is generally observed because of stretching vibrations of lead-iodide ions. In UV–visible (UV-Vis) little effect was observed on the energy band gaps i.e. 1.93 eV for 1.05 M:1 M and 1.96 eV for 1.10 M:1 M. The electrochemical impedance spectroscopy (EIS) measurements were performed for electronic charges accumulation on the surface of the films which showed semi-circles Nyquist plots and frequency dependent Bode plots were used to find electron lifetime. The charge transfer resistance (R ct) decreased from 52Ω to 45Ω and electron life time were approximately equal to 0.10 s and 0.09 s for the ratio of 1.10:1 and 1.05:1. I-V measurements showed an Ohmic contact formation providing insights into defect concentrations with a linear response to applied bias. Recombination lifetimes were investigated using transient photovoltage (TPV) at various biases, no correlation between the applied bias and recombination lifetime was found. Q-DLTS indicated presence of 3 trap centers for the charge carriers which were actively responsible for degradation of the perovskite material, these traps serve as recombination centres that reduce the overall power conversion efficiency (PCE) of solar cells. Photoluminescence spectroscopy (PL) analysis was done to verify the energy bandgap value which was found similar in comparison to UV–VIS. • CsPbI 2 Br perovskite thin films have been synthesized by simple solution processing method, and drop casting method was adapted for thin films preparation with ratios of 1.05:1 and 1.10:1. • Optical bandgap (1.93 eV) was also verified using Photoluminescence spectroscopy (PL) which is approximately similar in comparison to obtained from UV–VIS. • The charge transfer resistance (R ct) decreased from 52Ω to 45Ω for the ratio of 1.10:1 and 1.05:1 respectively. • From Ohmic and trap filled limited (TFL) recombination lifetimes were investigated using transient photovoltage (TPV) at various biases to determine recombination rates. • For 1.05:1 ratio, charge deep level transient spectroscopy (Q-DLTS) have shown 3 trap centers for the charge carriers. [ABSTRACT FROM AUTHOR]

In this study, we reported the sol-gel production of cerium (Ce) and beryllium (Be)-doped calcium aluminate (CaAl 12 O 19) and its luminescence properties for optically stimulated luminescence (OSL) dosimetry and light-emitting applications. Structural, morphological and elemental characteristics of the samples were examined by x-ray diffraction (XRD), Scanning electron microscope (SEM)/energy dispersive spectrum (EDS), x-ray fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) techniques. The maximum OSL intensity was achieved with 0.5 and 2% mol concentrations of Ce and Be dopants, respectively. We investigated the OSL and thermoluminescence (TL) properties of Ce and Be-doped CaAl 12 O 19 by measuring energy storage for 24 h, dose-response in the range of 0.1 and 20 Gy, and reusability of the samples for 15 cycles. Photometric properties of the phosphors were investigated by evaluation of CIE chromaticity coordinate (x, y), CCT, and colour purity using its corresponding photoluminescence (PL) emission spectra. We also applied computerized glow curve deconvolution (CGCD), various heating rate methods, and the T m -T stop procedure to determine the trap localizations associated with the TL glow curve. The results of this study point out that CaAl 12 O 19 crystals have the potential to be used as OSL dosimetry when appropriate dopants are used. This study may offer new possibilities in radiation dose detection and monitoring. • XRD, SEM&EDS and XRF analyses proved the CaAl 12 O 19 (CAO) ceramics were successfully synthesized via the Sol-Gel method. • TL, RL and PL emissions CAO ceramics originate from similar luminescence processes • OSL signals were found to be linear between 0.1 and 20 Gy, reusable up to 15 repeating experimental cycles, and low fade. • The trap parameters of the material were estimated using T m -T stop , various heating rates and CGCD techniques • The evaluated CIE chromaticity coordinates and color purity showed the phosphor is in the UV region of the color space. [ABSTRACT FROM AUTHOR]

In this study, the fabrication of single grain bulks (Y,Er)Ba 2 Cu 3 O 7−x "(Y,Er)−123" superconductors is well studied to enhance high superconducting performance in the mixed binary system between yttrium and erbium elements. A series of isothermal experiments of mixed (Y,Er) 2 BaCuO 5 "(Y,Er)−211" binary system has been prepared at various constant temperatures for 50 hours to optimize the heating pattern to produce large-sized (Y,Er)−123 bulks single domain. (Y,Er)−123 bulks were fabricated using the infiltration growth (IG) process. All samples obtained were studied by X-ray diffraction (XRD), Scanning electron microscope (SEM), Superconducting quantum interference device (SQUID), and trapped field measurements. In isothermal experiments, it revealed that the optimum temperature obtained to grow a good (Y,Er)−123 bulks was at 985 °C. All samples showed T c-onset from 89 K to 91 K indicating all samples show superconducting nature. Microstructural analysis indicated that the presence of non-superconducting (Y,Er)−211 fine particles within the (Y,Er)−123 matrix improved the J c values up to 41.60 kA/cm2. On the other hand, slow cooling bulk (Y,Er)−123 has been conducted after obtaining the optimum growth temperature window from the isothermal experiment. (Y,Er)−123 bulks were fabricated using a slow cooling IG process. It revealed that the homogenous distribution of (Y,Er)−211 particles in the (Y,Er)−123 matrix improved the superconducting performance, J c, and trapped field. As a result, J c obtained for a single domain of (Y,Er)−123 bulk was 43.03 kA/cm2 at 77 K, H// c -axis and self-field. • This approach is useful and simple to obtain a good optimum temperature for binary system Y,ErBCO. • We use Y211 and Er211 powders synthesis by conventional solid-state method. • An isothermal study was conducted to produce Y,Er-BCO bulk superconductor. • High critical current density, J c was greatly improved. [ABSTRACT FROM AUTHOR]

The microstructure, phase composition, precipitates evaluation, casting, and mechanical properties of the novel cast Al-4Cu-2.1Er-1Mg-0.2Zr-0.2Cr-0.15Fe-0.15Si-0.1Ti alloy were analyzed using by optical microscope, scanning and transmission electron microscopes, differential scanning calorimetry, thermodynamic calculations, hot cracking and mechanical properties measurements. The positive effect of Cr as a substitution of Mn on plasticity and precipitation strengthening was demonstrated. The 0.2Zr, 0.2Cr and 0.1 Ti as a grain refiners provide a fine grain size of 25 μm in the as-cast state due to primary Al 75–80 Cu 10–12 Er 3–4 Cr 7 phase particles formation as a nucleation centers of Al. The hot cracking index (HCI) of the AlCuErMgCr alloy was 12–14 mm which is similar with HCI of the cast Al-Si-Cu-Mg alloys. The good casting properties in the AlCuErMgCr alloy achieved due to a fine grain structure and narrow solidification range. The contribution of the Al 3 (Zr,Er) (40 nm), Al 45 Cr 7 (6 nm), and S'(θ') (100/5 nm) precipitates is 38.5 MPa, 140.4 MPa, and 198.9 MPa and the calculated contribution from dislocation and precipitates is 262.3 MPa. The ultimate tensile strength (UTS) and elongation (El.) of the AlCuErMgCr alloy are 372 MPa and 6% which is higher in 16.6% and 150%, respectively, than in the Mn-containing alloy. Novel alloy has an excellent combination of yield strength (YS) and plasticity at 20–250°C. The YS and El. are 301 MPa and 6% and 225–250 MPa and 4.6–11.5% at 20 and 200–250°C, respectively. The rupture strength at 250°C after 100 h (σ 100 250) is 106 MPa. Mechanical and casting properties of the novel alloy are superior to the properties of commercial 201.0 (Al-Cu-Mn-Mg-Ag-Ti) alloy. • Cr, replacing Mn, had a positive impact on both plasticity and precipitation strengthening. • 0.2Zr, 0.2Cr, and 0.1Ti as grain refiners resulted in the formation of primary Al 75–80 Cu 10–12 Er 3–4 Cr 7 phase particles. • The AlCuErMgCr alloy displayed an ultimate tensile strength (UTS) of 372 MPa and an elongation (El.) of 6%. • The rupture strength at 250°C after 100 hours was determined to be 106 MPa. [ABSTRACT FROM AUTHOR]

The microstructure and properties of the aged Cu-Cr-Zr-Nb alloy were studied by means of hardness tester, universal tensile testing machine, conductivity meter, X-ray diffraction, scanning electron microscope, and transmission electron microscope. The results indicated that the hardness and TS (tensile strength) of the Cu-Cr-Zr-Nb alloy increased first and subsequently decreased with increasing the aging temperature. Nevertheless, the electrical conductivity is gradually increasing. The aged Cu-Cr-Zr-Nb alloy was mostly made up of Cu matrix, Cr particles, Cr 2 Nb, and CuZr compounds. Due to the effects of dislocations accumulated by cold drawing and twins produced during the aging process, the softening temperature of the alloy reached 590 ℃. When the Cu-Cr-Zr-Nb alloy was aged at 490 ℃, < 111 > replaced < 110 > in the optimal orientation of the alloy, and the KAM (kernel average misorientation) value inside the alloy was the largest. The alloy exhibited great comprehensive properties at 490 ℃ for 1 h, with a hardness of 144.4 HBW, a TS of 521 MPa, and an electrical conductivity of 78.3%IACS. The contribution value of YS (yield strength) at different aging temperatures was further calculated. The computational results showed that precipitation strengthening was the main strengthening mechanism of the Cu-Cr-Zr-Nb alloy, and fine-grained strengthening and dislocation strengthening simultaneously played a supplementary role. • Due to the effects of dislocations accumulated by cold drawing, precipitation strengthening of Cr and twins produced during the aging process, the softening temperature of the Cu-Cr-Zr-Nb alloy reaches 590 ℃. • The Cu-Cr-Zr-Nb alloy exhibits great comprehensive properties at 490 ℃ for 1 h, with a hardness of 144.4 HBW, a tensile strength of 521 MPa, and an electrical conductivity of 78.3 %IACS. • The computational results show that precipitation strengthening is the main strengthening mechanism of the Cu-Cr-Zr-Nb alloy. [ABSTRACT FROM AUTHOR]

Developments in engineering and medicine have allowed patients' health and quality of life to be supported by implants. Unfortunately, widely used titanium-based alloys with aluminum and vanadium are not ideal materials. The first problem is a mechanical mismatch between human bone and the implant material, and the second issue is the presence of Al or V, which are harmful for the human body and health. This article focuses on the holistic design and production of titanium-based materials with vital elements. The zoned, gradient element can exhibit better mechanical properties and improve the connection between the implant and the bone. The samples in two constructions were built with two different zones. The powders for samples were prepared using the powder metallurgy technique with sieve separation. Phillips X-ray X′Pert diffractometer and PDF4 + database performed the phase composition analysis. The Scanning electron microscope allow the samples observation. Stereological methods assessed porosity and PAR M370 Scanning Electrochemical Workstation. The designed technology based on the powder metallurgy method allows for producing functional, two-zoned graded materials with variable porosity. The phase composition analysis confirmed partially synthesis. Additionally, the observation of the microstructure of the sintered samples revealed the presence of two permanently connected zones. Preliminary mechanical research was conducted to evaluate the potential use of the material as an implant material. The proposal to use two-zone construction of components for implants is dictated by the possibility of personalizing implants for patients, taking into account personal characteristics and needs. [Display omitted] • The functionally graded materials based on vital elements were successfully fabricated using powder metallurgy method. • Highly porous FGM with interconnected porosity was prepared by powder metallurgy. • The porous and microstructure evolution in each gradient layer of FGM is revealed. • The effect of Tin use as Process Control Agent were confirmed and allow to obtain more uniform powders. [ABSTRACT FROM AUTHOR]

This study used a sonochemical reactor to synthesize Co 0.50 Ni 0.50 La x Fe 2−x O 4 (0.00⩽x⩽0.2; step 0.05) spinel ferrites. X-ray diffraction spectra and scanning electron microscope (SEM) images were employed to verify and authenticate the physical characteristics, such as crystalline structure and morphology of the Co 0.50 Ni 0.50 La x Fe 2−x O 4 spinel ferrite particles. These structural analyses are targeted to confirm the singular-phase cubic Fd-3 m spinel ferrite nature. It has been noted from the SEM images that every particle resembles a sphere-like morphology. The real dielectric constants and dielectric loss of the prepared Co 0.50 Ni 0.50 La x Fe 2−x O 4 spinel ferrites were measured. The blocking (T B) and Curie (T C) temperatures of the spinel ferrites can also be explored and measured using temperature-dependent susceptibility and ultrasonic non-destructive techniques (NDT), respectively. The difference between the T B and T C is quite small. This observed difference implies that finding the phase transition temperature of spinel ferrites using ultrasonic NDT testing is a more flexible process than any other conventional technique. The room-temperature hysteresis shows that these La3+ doped Co 0.50 Ni 0.50 La x Fe 2−x O 4 ferrite samples might be more suitable for applications. • Influence of La3+ ions in Co 0.50 N i0.50 Fe 2 O 4 nanoferrite were explored. • Decrease in M s and T C was observed with increasing La3+ ions. • Phase transition explored through temperature-dependent susceptibility and ultrasonic measurement. [ABSTRACT FROM AUTHOR]

The Mg-Ni-based alloys have been extensively investigated as negative electrode materials in Nickel-Metal Hydride (Ni-MH) batteries. In this work, two Mg-Ni-based samples (Mg 71 Ni 29 and Mg 72.6 Ni 25.3 Gd 1.1) were prepared by means of melting. The X-ray diffraction (XRD), scanning electron microscope (SEM), galvanostatic charging/ discharging and other electrochemical measurements were used for the investigation. The results show that the Mg 71 Ni 29 and Mg 72.6 Ni 25.3 Gd 1.1 alloys include the characteristic peaks of Mg 2 Ni and the less strong characteristic peaks of Mg and MgNi 2 phases. The diffraction peak of the major phase Mg 2 Ni of the Mg 72.6 Ni 25.3 Gd 1.1 alloy is shifted to a small angle and its unit cell volume increases. With the addition of Gd, the alloy electrodes exhibits better cycling stability. After 50 charge/ discharge cycles, the capacity retention rate of the alloy electrode increase from 16% (Mg 71 Ni 29) to 22% (Mg 72.6 Ni 25.3 Gd 1.1). However, the maximum discharge capacity of the alloy electrode decrease from 134.3 mAh/g (Mg 71 Ni 29) to 91.9 mAh/g (Mg 72.6 Ni 25.3 Gd 1.1). The Mg 72.6 Ni 25.3 Gd 1.1 alloy possess lower limiting current density I L and exhibit relatively high corrosion resistance against the alkaline solution. After Gd doping, the charge transfer capacity of the Mg 72.6 Ni 25.3 Gd 1.1 alloy surface is increased. • The addition of Gd positively impacts the cycling stability of the alloy electrodes. • The Gd-doped alloy exhibits the superior corrosion resistance compared to the Gd-free alloy. • The electrode surface of the Gd-doped alloy demonstrates an augmented capacity for charge transfer. • The solid solubility of Gd atoms in the Mg-Ni-based alloys were verified. [ABSTRACT FROM AUTHOR]

Energy storage in flexible supercapacitor devices extensively depends on electrode design with good electrochemical as well as mechanical properties. Here, a cost-effective and scalable method is proposed for the synthesis of a reduced graphene oxide/ruthenium oxide (rGO/RuO 2) composite thin film for flexible supercapacitor. The successive ionic layer adsorption and reaction (SILAR) method used to synthesize rGO/RuO 2 composite electrode allowed the synthesis of amorphous RuO 2 with optimized rGO composition. The morphological structure of rGO/RuO 2 composite examined using a scanning electron microscope showed compact spherical microparticles coated on rGO sheets. The electrochemical measurements of rGO/RuO 2 composite electrode revealed that the composite material achieved a specific capacitance of 1371 F g−1 at a scan rate of 5 mV s−1. Due to the combined impact of rGO and RuO 2 , a flexible solid-state asymmetric supercapacitor (FSS-ASC) of configuration rGO/RuO 2 /PVA-H 2 SO 4 /WO 3 exhibited C s of 114 F g−1 at 5 mV s−1 with 88% of capacitance retention after 5000 galvanostatic charge-discharge (GCD) cycles. The FSS-ASC provided a remarkable specific energy of 23 Wh kg−1 and a specific power of 613 W kg−1. The electrochemical features of rGO/RuO 2 composite show a promising way to fabricate flexible supercapacitors. [Display omitted] • The rGO/RuO 2 composite synthesized using facile SILAR method. • The synergistic impact between rGO and RuO 2 enhanced capacitive performance. • The C s of 1371 F g−1 was achieved for rGO/RuO 2 electrode in 1 M H 2 SO 4 electrolyte. • The FSS-ASC device delivered an S E of 23 Wh kg−1 at 613 W kg−1 S P. [ABSTRACT FROM AUTHOR]

The Cd 0.96 Zn 0.04 Te (211) crystal is widely recognized as the optimal substrate for epitaxy growth of HgCdTe material. However, its further application is significantly hindered by size and cost limitations. CdZnTe films grown on GaAs substrates by close spaced sublimation may present a promising substrate for epitaxial HgCdTe. In this work, we successfully prepared high quality CdZnTe (133) films on GaAs (211) substrate. The results of scanning transmission electron microscope and selected-area electron diffraction reveals different crystal orientation between GaAs and CdZnTe, which can effectively accommodate the large lattice mismatch. The crystalline quality of the CdZnTe film was improved by introducing a ZnTe buffer layer, resulting in reduction in the etch pit density from 3.2 × 105 to 2.6 × 105 cm−2; a decrease in the full width at half maximum from 57 to 34″, and a lower surface roughness from 9.88 to 3.69 nm. The incorporation of the ZnTe buffer layer prompt the formation of CuPt-type ordered CdZnTe regions at the interface between the CdZnTe film and ZnTe, efficiently relieving the misfit strain originating from GaAs and ZnTe interface. Additionally, a two-step growth method was employed to adjust the Zn content of the film surface by controlling the growth temperature. Diverse lattice constant CdZnTe film is ready to further epitaxial growth of HgCdTe material with different bandgap. • CdZnTe (133) epitaxial films were prepared on GaAs (211) by Close Spaced Sublimation. • High quality CdZnTe (133) films are prepared by introducing a Zn 1−x Cd x Te/ZnTe buffer layer. • The formation of a CuPt-type CdZnTe ordered regions effectively release the misfit strain. • A two-step growth of CdZnTe was employed to precise control over the Zn content in the films. [ABSTRACT FROM AUTHOR]

The present paper is centred around the investigation of the structural, electrical, and magnetic properties displayed by the novel perovskite polycrystalline La 0.7 Pb 0.3 Mn 1−y V y O 3 (y = 0 – 0.1) prepared via the conventional solid-state technique. The structural properties of the samples were assessed through the utilisation of X-ray diffraction (XRD) analysis. Subsequently, the obtained diffraction data underwent refinement employing Rietveld refinement techniques in order to determine the structural parameters of the samples a , b , c , V and Mn–O bond length and angle. The study of X-ray diffraction (XRD) peaks reveals that all the samples exhibited crystallization in a single phase, devoid of any impurities. All of the samples exist in rhombohedral orientation with a space group of R-3c. The tolerance factor of the samples was calculated in order to assess the severity of lattice distortion, decrease from 0.872 (y = 0) to 0.831 (y = 0.1). The microstructural characteristics of the samples were analysed using a field-emission scanning electron microscope (FESEM). The morphology results reveal that a rise in the amount of V leads stimulates the grain growth in the sample, as evidenced by the increase in grain size from 2.17 µm (y = 0) to 3.71 µm (y = 0.1). The Fourier transform infrared (FTIR) analysis revealed an absorption range of 500 – 600 cm-1, which is indicative of the Mn–O bond deformation vibration. This observation suggests the presence of a MnO 6 bond in the sample. The Tauc plots derived from the UV-Vis spectroscopy data reveal a notable increase in the optical bandgap (E opt) as the concentration of V increases. Specifically, the E opt values rise from 1.71 eV (y = 0) to 2.30 eV (y = 0.1), falling within the range typically observed for semiconductor materials. A distinct metal-insulator transition was observed in all of the samples, exhibiting a range of T MI values ranging from 250 K to 292 K. The scattering model was employed to determine the itinerant e g behaviour in the low temperature region, whilst the SPH model was used to explore the conduction behaviour in the high temperature region. The magnetic characteristic of the samples was investigated using the Alternating Current Susceptibility (ACS) and Vibrating Sample Magnetometer (VSM) techniques, which confirms the existence of a shift in phase from ferromagnetic (FM) to paramagnetic (PM). The T C value exhibits a declining trend from 298.8 K (y = 0) to 274.8 K (y = 0.1). [Display omitted] • The La 0.7 Pb 0.3 Mn 1−y V y O 3 (y = 0 – 0.1) samples crystallized in Rhombohedral structure with a space-group of R-3c. • Modification in metal-insulator transition as T MI values decrease from 292 K (y = 0) to 250 K (y = 0.1) • T C value indicate a decreasing pattern as the V concentration increases, from 298.8 K (y = 0) to 274.8 K (y = 0.1) [ABSTRACT FROM AUTHOR]

Multiferroics, specifically magneto-electric materials that couple the ferroelectric and ferromagnetic responses, have boosted researchers' interest in fabricating energy storage devices. For this purpose, we synthesized the perovskite-based triphasic composites using sol–gel auto- combustion and solid–state reaction route. The presence of pure perovskite phases and lattice parameters were noted by X-ray diffraction analysis. Further, Rietveld's refinement confirmed the precision of phase analysis with a high degree of goodness of fit. The homogenous and uniform growth of grains for 0.1BiFeO 3 + 0.7BaTiO 3 + 0.2Nd 0.5 Dy 0.5 MnO 3 composite was seen by field emission scanning electron microscope and scanning transmission electron microscope. The perfect match between empirical elemental composition and prepared composites was determined by energy-dispersive X-ray spectroscopy. The highest remanent, maximum polarization, recoverable energy density, and ferroelectric efficiency were observed for the composite mentioned above. Furthermore, mathematical modeling via Python was carried out with ferroelectric data, and a mathematical relation was derived between the electric field and dielectric constant to observe the electro-optic Kerr effect. Similarly, the above-mentioned composite was seen with the highest coercive field, remanent, and maximum magnetization by M–H loops. Finally, the variation in polarization by changing the magnetic field confirmed M-E coupling and declared this 0.1BiFeO 3 + 0.7BaTiO 3 + 0.2Nd 0.5 Dy 0.5 MnO 3 triphasic composite as best candidate for energy storage devices. [Display omitted] • Facile synthesis of impurity free and stable perovskite-based ternary composites at RT • Optimization of ferroelectric hysteresis loops by inculcating magnetic phases in composite samples • Mathematical modelling-based optimization of electro-optic Kerr effect in composite samples • Transformation from diamagnetic to antiferromagnetic attributes and magnetic reversal behavior • Co-existence of ferroelectric and magnetic orderings empowering M-E coupling via strain mediation [ABSTRACT FROM AUTHOR]

Surface coating had been widely acknowledged as an effective method to improve the electrochemical performance of the cathodes for lithium-ion batteries (LiBs). In this study, a high-conductivity Ti 0.05 V 1.96 O 5 (TVO) coating was successfully deposited on the surface of Li(Ni 0.8 Co 0.1 Mn 0.1)O 2 (NCM811) particles. The crystal structure, micro morphology and element composition of the resulted NCM811 @TVO samples were evaluated using X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. Subsequently, the electrochemical performance of NCM811 @TVO cathodes were evaluated by galvanostatic charge/discharge tests (GCDT) and electrochemical impedance spectroscopy (EIS). The experimental results suggested that incorporating a TVO coating on the NCM811 cathode effectively enhanced both the rate capability and the cycling stability. Furthermore, first-principles calculation based on the density functional theory (DFT) were performed to elucidate the distinct electronic structure and Li ion migration behavior of V 2 O 5 and TVO. The DFT calculation demonstrated that the introduction of Ti ions into the V 2 O 5 leaded to the formation of small polarons and excessive free electrons, while significantly reduced the energy barrier for Li+ migration along [100] direction. [Display omitted] • The T 0.05 V 1.96 O 2 (TVO) coating layer was successfully prepared. • The TVO coating was provided with enhanced conductivity and Li+ diffusion coefficient. • First-principles calculation was used to investigate the structure and properties of the TVO coating. [ABSTRACT FROM AUTHOR]

In this study, the effect of composite shear flow casting (CSFC) on microstructure and hot deformation process of Ni-based superalloy Udimet720Li has been investigated. Udimet720Li superalloy was produced by using CSFC and conventional casting methods, followed with the same isothermal forging process. The microstructures of both CSFC and conventionally solidified (CS) samples were characterized using optical microscope, scanning electron microscope, energy dispersive X-ray spectroscopy and electron backscatter diffraction. Results show that the CSFC sample owns excellent microstructural uniformity with a reduced area fraction of segregation regions, leading to a wider processing window for subsequent deformation, compared to the CS sample. Besides, the deformation resistance and the thermal workability of CSFC sample are significantly improved because of the homogeneous microstructure, resulting in the uniform deformation during subsequent isothermal forging. • Ni-based superalloy Udimet720Li was produced by using composite shear flow casting. • The microstructure evolution of Udimet720Li was investigated. • The fracture mechanism of forged microstructure was analyzed. • The CSFC-processed Udimet720Li has homogeneous microstructure and superior deformation workability. [ABSTRACT FROM AUTHOR]

Dynamic mechanical properties of the selected laser melting (SLM)-NiCrFeCoMo 0.2 high-entropy alloy (HEA) are further improved by controlling the molten pool structure and the generation of σ-phase precipitation particles. In this study, a split Hopkinson pressure bar (SHPB) was used for testing the dynamical mechanical properties of the quenched SLM-NiCrFeCoMo 0.2 HEA specimens. Microstructure and volume fraction of the σ precipitates were characterized by X-ray diffractometry (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and the small angle neutron scattering (SANS) technique. After heating to 800 ℃, holding for 8 h and water quenching, the molten pool boundary of the SLM-NiCrFeCoMo 0.2 HEA disappear, and the ultimate compressive strength and the impact energy of specimens reach 1970 MPa and of 217.45 MJ·m−3, respectively. Due to the segregation of Mo elements in the molten-pool boundary of the as-build SLM-NiCrFeCoMo 0.2 HEA, more σ precipitates tend to form at the residual molten pool boundary of the quenched SLM-NiCrFeCoMo 0.2 HEA. The σ precipitates play key role in strengthening of the SLM-NiCrFeCoMo 0.2 HEA. • Annealed SLM- NiCrFeCoMo 0.2 HEA has larger ultimate compressive strength and the impact energy. • Lots of σ precipitates generate at the residual molten pool boundary. • Small angle neutron scattering technique is used to analyze the volume fraction of σ precipitates. • The σ precipitates play key role in strengthening of the SLM-NiCrFeCoMo 0.2 HEA. [ABSTRACT FROM AUTHOR]

It is recognized that new environmentally friendly and economical cooling methods are needed. In this paper, we focus on the effect of different doping amounts of Pr on the performance of magnetic refrigeration materials in the presence of trace doping of Co ions at the B-site. The samples La 0.67 Sr 0.33−x Pr x Mn 0.975 Co 0.025 O 3 (LSPMCO x = 0.10,0.125 and 0.15) in this paper were prepared by sol-gel method. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) diffraction data determined that the samples were pure phases without impurities belonging to the R-3c space group (No. 167). Scanning electron microscope (SEM) and transmission electron microscope (TEM) showed that the samples were not regular particles of submicron size, and the size of the grains decreased gradually with increasing Pr doping. The experimental data have shown that the samples underwent second order phase transitions near the Curie temperature (Tc). Tc is closest to room temperature at 300 K at a doping level of 0.10. The maximum magnetic entropy change (− ∆ S M max ) at 5 T is 3.79 (J/kg∙K) (x = 0.15) and the relative cooling power (RCP) is 352.78 (J/kg) (x = 0.15). The results demonstrated that the doping of Pr has an enhanced effect on the performance of the magnetic refrigeration La 0.67 Sr 0.33 Mn 0.975 Co 0.0 2 5 O 3 material. This may provide a reference for improving the performance of magnetic refrigeration materials in future research. • The maximum magnetic entropy change (− ∆ S M max ) with an applied magnetic field (H) of 5 T reached 3.73 J/(kg·K) at x = 0.125. • The values of LSPMCO (x = 0.10, 0.125 and 0.15) RCP were 107.41 (J/kg), 113.49 (J/kg) and 123.89 (J/kg) at 2 T. At H of 5 T X = 0.15 it reaches 306.28 (J/kg) which is 86 % of gadolinium. • LSPMCO has a large half-peak width of 92.84 at x = 0.15. LSPMCO has the potential to be further investigated as a magnetic refrigeration material. [ABSTRACT FROM AUTHOR]

In order to modify the mechanical and magnetic characteristics of high-entropy alloys (HEAs), phase transformation has been extensively studied. However, the impact of phase transformation on corrosion resistance has received less attention. In this paper, the intensive investigation of BCC/B2 to FCC phase transformation of equiatomic AlCoCrFeNi reveals the correlation between corrosion resistance and microstructure transformation under different heat treatment temperatures. Combined with differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscope (SEM) and electron backscattered diffraction (EBSD), the phase transformation of equiatomic AlCoCrFeNi heat treated with increasing temperature is BCC + B2 (as-cast) → BCC + B2 (600 °C) → BCC + B2+ FCC +σ (850 °C) → BCC + B2+ FCC (1100 °C). Combined with the results of SKPFM, immersion tests, and electrochemical measurements, the alloy treated at 1100 °C has the most excellent corrosion resistance due to its unique phase composition with the highest FCC phase and no intermetallic. • The correlation between heat treatment temperature and corrosion resistance of equiatomic AlCoCrFeNi was studied. • The microstructure of AlCoCrFeNi is changed from BCC to σ + FCC + BCC (850 °C), and then to FCC + BCC (1100 °C). • With increasing temperature, the corrosion resistance of AlCoCrFeNi is gradually improved except for 600 °C. • AlCoCrFeNi treated at 1100 °C exhibits most excellent corrosion resistance due to maximum FCC phase without intermetallic. [ABSTRACT FROM AUTHOR]

In this study, graphite-reinforced 6201 aluminum alloy matrix composites were fabricated by multi-pass friction stir processing. The mechanical properties and electrical conductivity of the composites were tested, the microstructure and composition of the composites were analyzed by scanning electron microscope and Raman spectroscopy. The results showed that the graphite-reinforced 6201Al matrix composite achieved simultaneous improvement of mechanical and electrical properties compared to the base material, with a 19.5 % increase in ultimate tensile strength and a 1.2 % increase in electrical conductivity. Microstructural and compositional analysis revealed that the graphite reinforcement in the composites was significantly fragmented during FSP, and its size decreased while the number of atomic layers reduced with increase in FSP passes. A directly bonded Al-C interface is observed between the graphite reinforcement and the matrix, and no interface products such as Al 4 C 3 were generated. The graphite reinforcement in the matrix simultaneously serves as a hindrance to dislocation motion and the expansion of microvoids during the tensile process, thereby leading to an enhancement in the tensile strength of the composite. The improvement in the electrical conductivity of the composite is attributed to two factors. On one hand, the structure and properties of graphite-reinforced phase is transformed to be closer to graphene after the severe plastic deformation during FSP process. On the other hand, the directly bonded Al-C interface between the matrix and the reinforcement is able to transfer electrons across the interface. • Mechanical and electrical performance of aluminum were simultaneously enhanced. • Severe plastic deformation decreased the number of atomic layers of the graphite. • Directly bonded Al-C interface between matrix and reinforcement is observed. [ABSTRACT FROM AUTHOR]

The aim of this paper is to develop a protective coating with both corrosion resistance and microbially-influenced corrosion resistance. We reported a Cu 55 Ti 25 Zr 15 Ni 5 amorphous powder, which was deposited into a coating by high velocity air-fuel spray. The coating was characterized via X-ray diffractometer, field-emission scanning electron microscope, and transmission electron microscope. For the electrochemical behavior, potentiodynamic polarization and electrochemical impedance spectroscopy were employed. Antibacterial property was assessed in terms of the inhibitory effect on Pseudomonas aeruginosa. The study findings revealed a crystallization temperature of 465 ℃ for the powder. The coating was dense with a lamellar structure, consisting of amorphous phase, Cu 0.81 Ni 0.19 and tetragonal-ZrO 2. In seawater, the coating showed a polarization resistance of 8581 Ω·cm−2, with corrosion dominated by Warburg diffusion. The coating formed a natural Cu 2 O-ZrO 2 -TiO 2 film, while the corrosion products consisting of CuO, ZrO 2 , and TiO 2. Notably, the coating displayed a bactericidal rate of (83.1 ± 4.5)% within 24 h. This work provided valuable insights into the preparation of Cu-based amorphous coating, while demonstrating its potential to resist microbially-influenced corrosion. • Developed a Cu 55 Ti 25 Zr 15 Ni 5 amorphous powder and deposited it into a coating. • Zr/Ti oxidized preferentially during deposition, causing partial crystallization. • Over 80% sterilization rate of the coating within 24 h. [ABSTRACT FROM AUTHOR]

High anti-corrosion Mg alloys is desirable to expand their industrial applications. Herein we report an outstanding corrosion resistance of dual-phase Mg-8Li-Y alloy using ultrahigh pressure (UHP) technology. The average corrosion rate is ∼0.47 mm/y, overwhelming the majority of Mg-Li alloys reported hitherto. In-situ X-ray diffraction and scanning electron microscope observation demonstrate that a unique multiple-film on UHPed Mg-8Li-Y alloy attributes to the excellent corrosion resistance, which origins from the dynamic dissolution/regeneration of Li 2 CO 3 -rich composite film, thus effectively prohibiting corrosion solution permeation. These results provide some implications to design good anti-corrosion coating for Mg, ever stainless Mg alloys. ● Y-rich particle dimension is reduced by ultrahigh pressure treatment. ● The corrosion rate of Mg-8Li-Y-UHP-700 is only ∼0.47 mm/y. ● The compact composite oxide film attributes to outstanding corrosion resistance. ● Oxide film bestows dynamic dissolution/regeneration and self-repair characters. [ABSTRACT FROM AUTHOR]

It is a challenge to improve the corrosion rate and blood compatibility of biomedical magnesium alloy implants in human body. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were used to study the Properties of K 2 ZrF 6 modified AZ31 magnesium alloy composite coating. The corrosion behavior of the sample in simulated body fluid (SBF) was evaluated by hydrogen evolution corrosion, potentiodynamic polarization cur ve and electrochemical impedance spectroscopy. The results show that the corrosion resistance of magnesium alloy is significantly improved by composite coating. The wettability test shows that K 2 ZrF 6 greatly improves the biocompatibility of MAO coating on magnesium alloy. The hemolysis test shows that the composite coating makes magnesium alloy have low hemolysis rate. The increase of PH value and magnesium ion concentration in solution caused by corrosion of magnesium alloy can be adjusted by adding K 2 ZrF 6. The corrosion resistance mechanism of MAO coating on K 2 ZrF 6 modified magnesium alloy was discussed. In this experiment, the optimum amount of K 2 ZrF 6 is 4 g/L. • MgO/K 2 ZrF 6 composite coating on the surface of magnesium alloy was successfully prepared. • K 2 ZrF 6 helps to improve the corrosion resistance of magnesium alloy microarc oxide coatings. • Magnesium alloy can be widely used in medical field by MgO/K 2 ZrF 6 composite coating. [ABSTRACT FROM AUTHOR]

A Co-free perovskite material, La 0.7 Sr 0.3 Cu 0.15 Fe 0.85 O 3-δ , is synthesized and electrochemically characterized to evaluate its potential application as electrocatalyst in the air electrode of solid oxide cells. The powder was firstly synthesized by the sol-gel method and subsequently morphologically and structurally characterized by scanning electron microscope and X-ray diffraction. Symmetrical circular button cells featuring Sm-doped ceria (20% Sm) as supporting electrolyte and La 0.7 Sr 0.3 Cu 0.15 Fe 0.85 O 3-δ as electrocatalyst were manufactured to carry out electrochemical investigations. Two different electrode morphologies are analyzed. In the first structure, the La 0.7 Sr 0.3 Cu 0.15 Fe 0.85 O 3-δ calcined powders are directly deposited by slurry coating on a dense sintered supporting pellet of Sm-doped ceria. In the second electrode configuration, the precursor solution of La 0.7 Sr 0.3 Cu 0.15 Fe 0.85 O 3-δ impregnates a porous scaffold of Sm-doped ceria, previously deposited and co-sintered with the supporting electrolyte. The performance of the samples was studied by means of electrochemical impedance spectroscopy, measuring polarization resistances of 0.0153 Ω∙cm2 at 700 °C and 0.052 Ω∙cm2 at 600 °C for the slurry coated and infiltrated electrodes, respectively. These values, according to the authors knowledge, are amongst the lowest ever obtained for Co-free solid oxides electrodes. However, the very high electrocatalytic activity obtained at intermediate temperatures is not accompanied by chemical stability over time. • The use of cobalt is discouraged in the next generation of energy conversion devices. • A Co-free electrocatalyst, LSCuF73, for the air electrode of SOCs is synthesized. • LSCuF73 is electrochemically tested by EIS. • LSCuF73 shows high electrochemical activity towards ORR at 600–700 °C but insufficient chemical stability. [ABSTRACT FROM AUTHOR]

In-situ compression of Cu 38 Zr 54 Al 8 metallic glass micropillars in a scanning electron microscope was performed together with continuous acoustic emission recording on samples in the as-cast state and after pre-deformation by high pressure torsion. A size effect was detected in both shear band operation and acoustic emission signal, irrespective of the preliminary deformation. This phenomenon was explained by the size dependent compliance of the pillar/indenter system. Differences between acoustic emission signals from the as-cast and pre-deformed states indicated changes in the shear band formation mechanism due to high pressure torsion. These differences were clear in the elastic regime of the in-situ compression and supported the role of rejuvenation in stabilization of unstable shear bands. • In-situ micro-compression and AE-signal detection carried out on CuZrAl BMG • Size effect explained by compliance of the pillar/indenter systems • Role of rejuvenation is supported in stabilization of unstable shear bands. [ABSTRACT FROM AUTHOR]

Novel ternary Zn-Cu-xAg alloys are designed and fabricated by the casting method under a vacuum atmosphere and then homogenized at 350 °C for 15 h. The effect of Ag concentration (x: 0, 1, 2, 3, and 4 wt%) on microstructure, hardness, in vitro corrosion, biodegradability, and bacterial sensitivity was studied systematically. The structural analysis of the alloys was investigated by using a scanning electron microscope (SEM-EDS), and an optical microscope (OM). Besides, phase characterization of the samples was conducted using X-ray diffraction (XRD). The degradation behaviors of the alloys were determined under in vitro conditions, electrochemical polarization, and immersion tests (up to 21 days) in artificial urine (AU) solution. The maximum hardness value for Zn-1Cu-4Ag alloy was about 2.38 times higher than pure Zn due to solid-solution strengthening and precipitation hardening of (Ag, Cu)Zn 4 phases. The highest and lowest I corr values, reference also corrosion rate, were calculated in Zn-1Cu and Zn-1Cu-3Ag alloys as 17.13 and 1.318 mA·cm−2, respectively. The alloys' bacterial sensitivities were evaluated with the disc diffusion test for E. coli and S. aureus. The inhibition ratio of the Zn-1Cu-1Ag was higher than the inhibition rates of the other alloys on E. coli and S. aureus. In addition, the biological properties of the generated material were promising by altering cell survival/death ratio in both prostate epithelial and bladder cancer cells related to their use potential in urology. • Novel Zn-Cu-Ag alloys were fabricated under vacuum for medical implant applications. • Varying Ag concentrations affected microstructure, hardness, biodegradability, and bacterial sensitivity. • Zn-1Cu-4Ag showed about 2.38x higher hardness than pure Zn due to solid-solution strengthening. • Zn-Cu-1Ag showed higher bacterial inhibition rates than other alloys, demonstrating potential use in urology. [ABSTRACT FROM AUTHOR]

The structure of a series AB 2 Laves-type metal hydride alloys, in which Ce was doped into Ti 0.24 Zr 0.76 Ni 1.15 Mn 0.7 V 0.15 and annealed the alloys, was studied and correlated to hydrogen storage properties and electrochemical performances. X-ray diffraction, scanning electron microscope, and energy-dispersive spectroscopy results revealed that Ce formed a CeNi 3 secondary phase instead of entering the Laves phases. The synergistic effect of the CeNi 3 and (Ti,Zr)Ni phase improved the hydrogen storage and electrochemical discharge properties of the Ce-doped (Ce 0.02) alloy. Especially, the secondary phases could decrease the hydrogen absorption plateau, reduce the hysteresis phenomenon, and increase the hydrogen storage capacity (from 0.9 wt% to 1.4 wt% at 25 ℃). The formation of CeNi 3 H x hydride on the surfaces of alloy electrodes led to a higher discharge capacity (∼500 mAh/g) and a faster activation rate. The Ce 0.02 alloy also showed a good cyclic stability ∼82.08%, after 500 charge-discharge cycling, which could be ascribed to the good corrosion resistance of the CeNi 3 phase on the surface of alloy. In addition, annealing treatment promoted the depletion of (Ti,Zr)Ni secondary phase and the transformation from the C14 to C15 phase. The Ce-doped AB 2 alloy can be used as a hydrogen storage and hydride battery electrode material. • Annealing resulted in the transformation from the C14 to C15 Laves phase. • Full discharge capacity of Ce 0.02 alloy as an anode reaches 500 mAh/g at 10 mA/g. • Synergistic effect of the CeNi 3 and (Ti,Zr)Ni phases on the Laves phases. • Secondary phases improves discharge and hydrogen storage capacity, and HRD ability. [ABSTRACT FROM AUTHOR]

An equiatomic AlCrCuFeNi high entropy alloy (HEA) was synthesized by arc melting. The as-cast material exhibits the formation of the two-phase structure consisting of BCC and FCC phases. Different heat-treatment schedules were adopted in this investigation for the systematic understanding of the elemental distribution, microstructural evolution and solidification behavior of the alloy. Light microscope and scanning electron microscope (SEM) with EDS analysis was extensively used to characterize the alloy. The results indicate the as-cast material has the primary phase of dendritic structure. The heat-treated sample at 1300 °C, followed by water quenching as well as furnace cooling, primarily showed the Fe-Cr rich BCC phase formation in the dendritic region. The interdendritic space is enriched in Al-Ni rich B2 phase and the Cu rich phase. These outcomes have proximity to the equilibrium phase predictions performed based on the CALPHAD approach. The element Cu plays a crucial role in affecting the solidification behavior of the alloy in the temperature range of 900–1100 °C. This work has shown why understanding the microstructure evolution and solidification behavior is more important in HEAs for their potential future applications. • An equiatomic AlCrCuFeNi HEA was synthesized by arc melting. • Sequential treatments from liquid to solid state gives rise to a highly heterogeneous structure. • Alloys exhibits two-phase structure of BCC and FCC in as-cast state. • The dendritic region showed Fe-Cr rich BCC and interdendritic in Al-Ni and Cu rich elements. • Cu plays a crucial role in affecting the solidification behavior of the alloy. [ABSTRACT FROM AUTHOR]

The thermal stability of materials directly influences their applications. This present work investigates the difference of thermal decomposition behaviors of alpha (α) and beta (β) manganese dioxide (MnO 2) nanorods. Differential scanning calorimeter coupled with thermogravimetric analysis is conducted to find the difference of thermal process. The X-ray diffraction analysis and scanning electron microscope are employed to test crystal structures and morphologies at various roasted temperatures, respectively. The activation energy and Debye temperature are calculated to explain the difference in the decomposition process. It is found that β-MnO 2 can be fully converted to Mn 2 O 3 after roasting at 650 °C, whereas only part of α-MnO 2 has changed. Besides, the β-MnO 2 nanorods go through a continuous thinning from room temperature to 500 °C, while the morphology of α-MnO 2 remains the same until it reaches over 300 °C. These results suggest that α-MnO 2 nanorods have better thermal resistance than β-MnO 2 , which could facilitate the selection of thermal stable materials for electrochemistry industries and energy materials application. • The evolution of two types MnO 2 nanorods morphologies are investigated when roasting. • The different thermal properties of α- and β-MnO 2 nanorods are reported at different temperatures. • The kinetics of thermal decomposition reaction of α- and β-MnO 2 nanorods are calculated and analyzed. • The first principles are employed to explained the difference on thermal properties of two types MnO 2. [ABSTRACT FROM AUTHOR]

Since triethylamine (TEA) is potentially harmful to the human body and the environment, it is necessary to create an efficient gas sensor for TEA decoration. In this work, novel catalytic RuO 2 nanoparticles-functionalized LaFeO 3 porous microspheres with high triethylamine-sensing performances were obtained via a simple hydrothermal method. The RuO 2 /LaFeO 3 composites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). Characterization results revealed that RuO 2 nanoparticles were homogeneously attached on the surface of porous LaFeO 3 microshperes. Gas-sensing tests exhibit that RuO 2 /LaFeO 3 nanocomposites show higher sensitivity, excellent selectivity and fast response and recovery towards trimethylamine (TEA). This work confirms the advantages of RuO 2 catalyst-loaded in gas detection. The RuO 2 /LaFeO 3 nanocomposites could be a promising candidate material for fast detection of trimethylamine. Image 1 • RuO 2 nanoparticles-functionalized LaFeO 3 porous microspheres were obtained via a simple hydrothermal method. • RuO 2 /LaFeO 3 nanocomposites show enhanced sensing properties to triethylamine. • This work confirms the advantages of RuO 2 catalyst-loaded in gas detection. [ABSTRACT FROM AUTHOR]

Ceramic nanoparticles reinforced aluminum matrix composite is a kind of promising materials in industrial production. However, its preparation is difficult due to the poor wettability between Al melt and ceramic particles and severe particle aggregation tendency. In this paper, the in-situ NdB 6 /Al–5Cu-0.3Mn nanocomposites were successfully prepared with the aid of melt spinning technology and ultrasonic vibration. Optical microscopy (OM), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to observe the microstructures of nano-NdB 6 /Al ribbons and NdB 6 /Al–5Cu-0.3Mn nanocomposites. The observation results were as follows: (1) more than 80% of the prepared NdB 6 particles were nanoscale; (2) the NdB 6 particles could be uniformly distributed in the Al–5Cu-0.3Mn alloy; (3) the NdB 6 particles had the effects of grain refinement and dispersion strengthening on the Al–5Cu-0.3Mn alloy; (4) the NdB 6 particles had a certain orientation relationships with α-Al. The tensile strength of Al–5Cu-0.3Mn alloy strengthened by the NdB 6 particles was improved significantly. The strengthening mechanisms were investigated in detail. • The in situ NdB 6 nanoparticles were successfully prepared by melt spinning technology. • The nano-NdB 6 particles could be uniformly distributed in the Al–5Cu-0.3Mn matrix. • NdB 6 particles could form perfect coherent interfaces with α-Al. • The strength of Al–5Cu-0.3Mn alloy strengthened by NdB 6 was improved significantly. [ABSTRACT FROM AUTHOR]

Highly conductive and transparent amorphous IZO films were fabricated by combining deep ultraviolet (DUV) excimer laser irradiation with solution combustion synthesis at low temperature. The influence of laser energy densities on the crystallinities, surface morphologies, and optical and electrical properties of the IZO films was investigated by using X-ray diffraction, scanning electron microscope, atomic force microscope, UV–vis spectroscopy, and Hall test. Additionally, Fourier-transform infrared spectroscopy showed that DUV laser irradiation led to the removal of organic residuals and hydroxyl groups. X-ray photoelectron spectroscopy showed that the percentage of metal‒oxide‒metal bonds in the IZO films increased significantly after the laser irradiation, which was beneficial for the electron transportation. As a result, the IZO films exhibited resistivity as low as 4.2 × 10−3 Ω cm with average visible transmittance as high as 91%, which yielded the highest Figure of Merit among the solution-processed transparent conducting films prepared at a temperature as low as 200 °C. Image 1 • Indium zinc oxide (IZO) films was prepared by a new solution processed method. • Effect of DUV laser irradiation on the properties of IZO films was investigated. • The IZO film exhibited high transparency and low resistivity at low temperature. [ABSTRACT FROM AUTHOR]

To improve the utilization efficiency of solar energy and separation of photogenerated carries, a novel three-dimensional (3D) WO 3-x /Bi/BiOCl hierarchical heterostructures with broad spectrum responsive photocatalytic activity have been fabricated through a facile solvothermal technique. The influences of varying loading of WO 3-x on the physical performances of the as-obtained composites were systematically characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, optical absorbance, photoluminescence and specific surface areas. The WO 3-x /Bi/BiOCl displayed a strong optical absorption from 250 to 2500 nm, and showed the superior photocatalytic performance in degradation of rhodamine B (RhB) than that of individual components. Among the as-prepared samples, the sample S24 with the appropriate content of WO 3-x displayed the best photocatalytic performance, which can photodegrade RhB with the efficiency of 100%, 100% and 96% under the UV light within 8 min, visible light within 3 min and near-infrared light within 120 min exposure, respectively. Furthermore, a plausible mechanism of the RhB degradation on WO 3-x /Bi/BiOCl photocatalysts under the near-infrared light irradiation was proposed according to the photocatalytic activity and radical species trapping experiments. Image 1 [ABSTRACT FROM AUTHOR]

A novel multicolor tunable phosphors Sr 3 Y(BO 3) 3 : x Tb3+, y Eu3+ (SYBO: x Tb3+, y Eu3+) had been obtained by conventional solid state reaction. The XRD patterns, scanning electron microscope (SEM) and the luminescence spectral were used to explore the phase composition and crystal structure, luminescence properties as well as the energy transfer and fluorescence lifetimes in detail. Under 376 nm wavelength excitation, the phosphors included green and red color derived from the representative emission wavelengths of the Tb3+ and Eu3+, respectively. Both the luminescence spectral and the fluorescence lifetimes demonstrated energy transfer in the SYBO: x Tb3+, y Eu3+ phosphors. When the doped Eu3+ concentration was 0.5 mol, the energy transfer efficiency was as high as 96.48% and 98.34%, respectively. Moreover, the energy transfer mechanism from Tb3+ to Eu3+ in the SYBO: x Tb3+, y Eu3+ phosphors was proved to be the dipole–dipole interaction. With the increase of the Eu3+ concentration, the color of the SYBO:xTb3+,yEu3+ phosphors could tune from green to light-white, and then to red owing to the existing energy transfer. Those results indicated that the SYBO: x Tb3+, y Eu3+ phosphors could be as promising multicolor tunable candidates for WLEDs under UV light. • Sr 3 Y(BO 3) 3 :Tb3+,Eu3+ was a novel single-phase multicolor tunable phosphor. • Effective energy transfer existed Tb3+-Eu3+ in Sr 3 Y(BO 3) 3 :Tb3+,Eu3+ phosphors. • The energy transfer mechanism in Sr 3 Y(BO 3) 3 :Tb3+,Eu3+ was dipole-dipole. [ABSTRACT FROM AUTHOR]

An in-situ temperature-controlled Raman spectroscopy aided unique electrode fabrication technique has been developed for Li-ion battery applications, ensuring superior electrochemical quality of the multi-porous LiCoO 2 films with higher stoichiometric purity of high temperature (HT)-LiCoO 2 phase, by observing the structural changes during the fabrication process and thus confirming the transformation from the low temperature (LT)-LiCoO 2 phase. This much desired simple process is not only free of any sort of binders or carbon additives but also works at atmospheric pressure, leading to a very simple deposition technique using a homemade and inexpensive set-up. Also, the time of depositions were varied and resultant films we investigated for their electrochemical performance. The high-resolution scanning electron microscope (SEM) observation has revealed not only a μm-size porous structure but also three-dimensional cross-link with 10 nm-level pores of the material, which ensured the much-desired porosity for high-performance cathodes. • Preparation process of high quality HT-LiCoO 2 electrode by a simple and a unique deposition technique. • Fabrication of thin films with additives and binders free. • Purity and phase formation monitored by in-situ analysis temperature-controlled Raman analysis. • Formation of a controlled double porous layers with high quality electrode. • The effect of the deposition parameters on the morphology and the electrochemical properties. [ABSTRACT FROM AUTHOR]

The freckle formation and evolution in directionally solidified single-crystal specimens with different thicknesses and abruptly expanding rectangular cross-section were investigated at different withdrawal rates. The microstructure was studied by optical microscope (OP) and scanning electron microscope (SEM), and the crystallographic orientation in freckle areas was characterized by electron backscattered diffraction (EBSD). The experimental results showed that the freckle was the most severe in specimens with a thickness of 10 mm at the same withdrawal rate, and the freckle chain was observed to form below an abruptly expanding cross-section ended at the expanding step. It was found that freckles formed exclusively on the edges of casting facing the central sprue of the shell mould. Findings reveal that freckles tend to form at the highest position of the mushy zone, mainly due to the thermosolutal convection and the radial flow caused by feeding behavior in the mushy zone. The freckle formation is pronounced at a low withdrawal rate, and can further generate stray grains. • Freckle formation is more pronounced at a low withdrawal rate of 1 mm/min. • Freckles form exclusively on the edges facing the central sprue of the shell mould. • Radial flow and feeding behavior play a major role in freckle position. • Freckle grains can evolve into stray grains at a low withdrawal rate of 1 mm/min. [ABSTRACT FROM AUTHOR]

A novel core-shell BaFe 12 O 19 @C composite with glucose-based carbon was successfully synthesized by the hydrothermal carbonization and subsequent calcinations. The phase structure, morphology and the microwave absorption properties of all the as-prepared samples were characterized by XRD, SEM and vector network analyzer, respectively. The results show that dielectric loss of BaFe 12 O 19 @C composites can be enhanced due to the introduction of carbon, which causes improved matching impedance and microwave absorption properties of BaFe 12 O 19 @C composites. The optimal maximum reflection loss is −73.42 dB with a thickness of 1.40 mm in the frequency range of 2–18 GHz. We believe that the BaFe 12 O 19 @C composites are promising candidates as highly effective microwave absorbers. Furthermore, the biomass carbon is expected to have further applications in the field of microwave absorption. • A novel core-shell BaFe 12 O 19 @C composite is synthesized by glucose as carbon source. • Biomass carbon effectively improves impedance matching and absorption of EM wave. • The optimal maximum reflection loss is −73.42 dB with a thickness of 1.4 mm. [ABSTRACT FROM AUTHOR]

In this work, nanocomposites with NiMoO 4 nanorod as core and NiMoS 4 nanosheet as shell with controlled sulfidation manner was obtained by one-step hydrothermal method. Characterization methods like scanning electron microscope and X-ray photoelectron spectrometer confirmed the well-designed core-shell structure and precisely-tuned composition. It exhibited superior electrochemical properties of high specific capacitance (832.3 F g−1 at current density of 5 A g−1), outstanding rate capability and stable cycling performance. With resultant as anode and reduced graphene oxide (rGO) as cathode, an asymmetric supercapacitor (ASC) was assembled and presented high energy density of 22.84 W h kg−1. Besides, cycling performance of the device is so outstanding that the capacity retention was up to 117.4% after 5000 cycles. Benefited from the synergistic effect between NiMoS 4 and NiMoO 4 components, large specific surface area and effective electron transportation from nanorod @ nanosheet structure, the excellent electrochemical performance indicates a good prospect of the material in the energy storage field. Image 1 • Complementary composition and well-designed structure was obtained simultaneously. • The resultant shows outstanding capacitive properties. • Assembled asymmetric supercapacitor exhibits excellent cycling performance. [ABSTRACT FROM AUTHOR]

In this research, a series of Tb3+ and/or Eu3+ doped KBaGd(WO 4) 3 (KBGW for short) phoshpors were prepared by sol-gel method and characterized by X-ray diffraction (XRD), FT-IR and Raman spectra, scanning electron microscope (SEM), excitation and emission spectra, and luminescent decay curves. The results of XRD, SEM, FT-IR and Raman spectra confirmed that a single phase of KBGW with smooth surface and uniform particle size can be synthesized by sol-gel method. Under 250 or 378 nm excitation, multicolor tunable emissions from green to red were achieved in the KBGW:Tb3+, Eu3+ phosphors by suitably controlling the ratios of Eu3+/Tb3+. The energy transfer efficiencies and mechanisms between Eu3+ and Tb3+ were investigated on the basis of photoluminescence (PL) spectra and luminescent decay curves, and a graphic analysis on the energy transfer process between Tb3+ and Eu3+ was presented. The temperature-dependent PL spectra of Eu3+ and/or Tb3+ doped KBGW were recorded and the thermal quenching behavior of the phosphors was analyzed in the framework of crossover model. At the end, green, red and white LEDs were fabricated with the as-prepared KBGW:Tb3+/Eu3+ phosphors, and the excellent electroluminescence parameters suggest that the KBGW:Tb3+/Eu3+ phosphors may be a component candidate for NUV excited WLEDs. • A color tunable KBaGd(WO 4) 3 :Tb3+/Eu3+ phosphor was firstly prepared by sol-gel method. • Its morphology, luminescent property and thermal stability were studied in detail. • The emission color was tuned from green to red by changing the doping ratio of Eu/Tb. • The energy transfer is demonstrated to be accomplished by dipole-dipole interactions. • Green, red and white LEDs were fabricated and their performance were investigated. [ABSTRACT FROM AUTHOR]

The interface evolution of Ti/Ni multi-layered composites produced by accumulative roll bonding after heat treatment was investigated in this study. The influence of heat treatment temperature on the microstructure and chemical composition of the Ti/Ni interfaces were examined by scanning electron microscope (SEM) equipped with an energy dispersive spectroscopy system (EDS) and transmission electron microscope (TEM). Phase composition and transition behavior of interfaces of the Ti/Ni multi-layered samples were studied by X-ray diffraction (XRD) and a differential scanning calorimeter (DSC). Only from the viewpoint of ΔG, ignoring the impact of other factors, the formation sequence of Ti–Ni IMCs is TiNi 3 →Ti 2 Ni→TiNi at the beginning of the diffusion reaction. With temperature increases, the microstructure of the composite is a mixture structure with alternating TiNi and Ti 2 Ni layers and the boundary morphology of each diffusion sub-layer transforming from an initial smooth and clear boundary, to the flocculent structure of the TiNi and Ti 2 Ni transition layer. The DSC results revealed a good martensitic and reverse transformation behavior from B2 to B19' of Ms at around 64 °C. With temperature increases, the austenite transformation temperature (T A) slowly shifts to high temperature and the change of martensite transformation temperature (T M) is not obvious. The phase transition hysteresis (A p -M p) from 5.9 °C of the 550 °C × 10 h heat treatment sample increases to 33 °C of the 770 °C × 10 h sample. • Ti/Ni multi-layer composites of Ti rich have been successfully fabricated by ARB. • Microstructure of Ti/Ni composites from layer changed to TiNi and Ti 2 Ni hybrid. • A martensitic transformation behavior from B2 to B19' appeared. [ABSTRACT FROM AUTHOR]

A non-rare-earth doped double perovskite La 2 ZnTiO 6 :Mn4+ phosphor with the single-phase was prepared by solid-state reaction. The composition and the distribution of La 2 ZnTiO 6 :0.5%Mn4+ phosphor was confirmed by the scanning electron microscope and energy-dispersive spectroscopy. The optical band gap of La 2 ZnTiO 6 was analyzed by density functional theory using the CASTEP code, which matched well with the result of diffuse the reflectance spectra (DRS). The excitation spectra of La 2 ZnTiO 6 :Mn4+ show two broad bands with peaks at about 342 nm and 504 nm. Emissions characteristic of Mn4+ ions from 650 nm to 750 nm were observed, with the 4E g →4A 2g transition near 708 nm. The result of the temperature-dependent photoluminescence shows good thermal stability and the luminous mechanism is explained by schematic energy level diagram of Mn4+ ion. Above all, a significant overlap was found between the far-red emission band of La 2 ZnTiO 6 :0.5%Mn4+ and the absorption spectrum of the phytochrome P FR , indicating that La 2 ZnTiO 6 :Mn4+ phosphor has great potentiality to be used as indoor plant artificial light. • The deep red phosphor La 2 ZnTiO 6 :Mn4+ for NUV-based white LEDs was synthesized successfully. • The double perovskite crystal structure, XRD, SEM and EDS of samples were studied in detail. • The electronic structure, optical band gap and photoluminescence properties of La 2 ZnTiO 6 :Mn4+ was studied systematically. • La 2 ZnTiO 6 :Mn4+ phosphor has potential applications in indoor plant artificial light. [ABSTRACT FROM AUTHOR]

Calcium aluminozincate phosphor, Ca 3 Al 4 ZnO 10 (CAZ) doped with Eu3+ has been synthesized using solid-state reaction (SSR), combustion (CS) and sol-gel (SG) methods for relatively improved luminescence performance and to optimize synthesis method. The X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) and PL decay measurements have been recorded for the detailed investigation of the luminescence properties of the as-synthesized phosphor. The thermoluminescence (TL) spectral study has been done to estimate the trap depth of the defect centres. The XRD peaks confirm the complete matching of the diffraction peaks of the as-synthesized sample with the standard data for Ca 3 Al 4 ZnO 10. The morphology of the sample synthesized via SG method shows agglomerated particles with average particle size smaller than the samples synthesized via CS and SSR method. The detailed investigation shows significant red emission enhancement in Eu3+ doped CAZ phosphor synthesized via SG method. The obtained results suggest that the Eu3+ doped CAZ phosphor synthesized via SG method could be a great choice as red emitter for applications in solid state lighting. • Optimized synthesis technique for calcium aluminozincate (CAZ) phosphors. • Phase confirmation observed in solid-state, combustion and sol-gel method. • Enhancement in red emission under blue excitation for sol-gel synthesized phosphors. • CIE coordinates are close to commercial red phosphor. • Conducted thermoluminescence studies to identify trap centres in CAZ phosphors for the first time. [ABSTRACT FROM AUTHOR]