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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]

La 10 Si 6 O 27 powder was synthesized by a high-energy ball milling method and its sintered body was prepared by spark plasma sintering (SPS) technology. Phase structure, microscopic morphology, density, porosity and oxide ion conductivity of La 10 Si 6 O 27 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Archimedes method and alternating current (AC) impedance spectrum, respectively. XRD results showed the ball-milled powder could form apatite-type La 10 Si 6 O 27 at 1400 ℃. The crystal structure of La 10 Si 6 O 27 sintered body remained stable. SEM results showed that La 10 Si 6 O 27 sintered body using SPS sintering method had better sintering between grains and a large reduction in open pores compared to conventional sintering. Grains of the sintered body were clearly visible and the grain size was uniform, about 1 µm. Archimedes method analysis showed relative density of La 10 Si 6 O 27 sintered body is 100%, and open porosity is 0. Electrical conductivity of La 10 Si 6 O 27 sintered body has an Arrhenius relationship with temperature. • SPS has the advantages of energy saving and emission reduction. • The σ of La 10 Si 6 O 27 using SPS at 1200 ℃ is better than that of conventional sintering at 1500 ℃. • The preparation methods of LSO have been enriched. [ABSTRACT FROM AUTHOR]

Abstract A series of Li 1+x ZnNbO 4 (0 ≤ x ≤ 0.05) spinel-structured ceramics were prepared by the conventional solid-state reaction. The phase composition, microstructure and relationship between the structure and microwave dielectric properties were investigated using X-ray diffraction, Raman spectroscopy, and scanning electron microscope. When x = 0.02, the outstanding microwave dielectric properties of Li 1+ x ZnNbO 4 (0 ≤ x ≤ 0.05) ceramics were achieved with ε r = 14.9 , Q × f = 104,600 GHz (at 9 GHz), and τ f = −64.0 ppm/oC. The dielectric constant and Q × f value decreased with the increase of Raman shift and FWHM of the A 1g mode. Furthermore, the large negative τ f of Li 1+ x ZnNbO 4 (0 ≤ x ≤ 0.05) ceramics could be modified by adding CaTiO 3 , and the 0.92Li 1.02 ZnNbO 4 -0.08CaTiO 3 ceramic sintered at 1120 °C for 4 h exhibited a near-zero τ f value of −1.4 ppm/oC along with a ε r of 21.3 and a Q × f value of 92,500 GHz. [ABSTRACT FROM AUTHOR]

Abstract Al-6Cu-6Mg-5Sn-3Ga- x In (x = 0, 0.5, 1, 3, 5. mass. fraction) alloys were prepared using melting and casting technique. The microstructures and properties of the alloys were investigated by X-ray diffraction, scanning electronic microscope/EDX, electron microprobe analysis, Vickers hardness, compression properties, immersion tests and electrochemical measurements. The results show that the main phases of the alloys with the indium element consist of α -Al, Al 2 MgCu, Mg 2 Sn and Al-In eutectic phases. The Al-In phases segregates in α -Al grain boundaries. The gallium elements solid solution in the matrix alloys. When the addition of In contents is 1 mass.%, the hardness of the Al-6Cu-6Mg-5Sn-3Ga-1In alloy reaches to 142HV, and the compressive strength up to 582 MPa. The Mg 2 Sn and the Al-In eutectic phases are the source of the degradation reaction, and the driving force to continue is the concentration of Al in the eutectic phase. The relationship between the degradation corrosion rate and temperature, indium element content and other factors were also discussed in this paper. Graphical abstract Image 1 Highlights • Microstructure, mechanical properties and corrosion behavior of Al-6Mg-6Cu-5Sn-3Ga- x In alloys were firstly investigated. • The investigated alloys mainly consist of α -Al matrix, Al 2 MgCu, Mg 2 Sn and Al-In eutectic phase. • The investigated alloy has a maximum degradation rate reaches 98.51 mg/(cm2 h) at 93 °C. [ABSTRACT FROM AUTHOR]

Abstract The Bi 0.95- x La 0.05 Y x Fe 0.95 Ti 0.05 O 3 (BYFO) (x = 0, 0.04, 0.06, 0.08, 0.10) ceramics were synthesized by traditional solid phase method. The samples for BYFO ceramics were tested for X-ray diffraction (XRD) techniques, magnetic hysteresis (M – H)loops, scanning electron microscope (SEM). The leakage current were weakened because highly dense microstructure and low porosity ceramics were compounded. When x = 0.06, remanent polarization (P r) is 0.3079 μC/cm2, and saturization polarization (P s) is 1.3542 μC/cm2 for BYFO ceramics. Saturation magnetization (M s) and remanent magnetization (M r) are increased to 1.91926 emu/g, 1.43179 emu/g respectively. The obtained values of the magnetodielectric coefficient (α MD) comes to maximum value, which is 15.64% for x = 0.08. Highlights • Bi 0.95- x La 0.05 Y x Fe 0.95 Ti 0.05 O 3 (BYFO) ceramics were synthesized by solid phase method. • The dielectric and magnetic properties were improved. • The magneticdielectric effect become more evident because of doped Y3+. [ABSTRACT FROM AUTHOR]

The purpose of this work was to investigate the feasibility of using sputtered Ti/W-Ti/Ti multilayer as diffusion barrier and buffer layers between β -Zn 4 Sb 3 thermoelectric (TE) material and Ag interconnect layer for mid-temperature TE module applications. Interdiffusion at the interface was examined by both scanning electron microscope and Auger electron spectroscopy. After penetrating the Ti buffer layer, Ag, Zn and Sb were successfully blocked by the W-Ti diffusion barrier layer. We also proved that the TE sample with diffusion barrier and buffer layers showed phase stability after high temperature aging. Also, the sheet resistance decreased as the temperature increased and it indicated good electrical properties at high working temperatures. In addition, the solid-liquid interdiffusion method was used to join the TE module, and the bonding remained stable at the TE module working temperature. [ABSTRACT FROM AUTHOR]

A novel kind of ternary nanocomposites, BaTiO 3 and NiFe 2 O 4 nanoparticles deposited on reduced graphene oxide nanosheets, was prepared via a three-step method. The phase structure, morphology, chemical composition, and magnetic properties were analyzed by powder X-ray diffraction (XRD) technique, field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), Raman spectroscopy and vibrating sample magnetometry (VSM) while the microwave absorption performance was investigated by vector network analyzer (VNA). The results showed the sample with 30 wt% reduced graphene oxide exhibits the most remarkable microwave absorption properties. The optimal reflection loss can reach −51.1 dB at 9.52 GHz with a coating layer thickness of only 2.9 mm and a broad bandwidth (RL < −10 dB) of 3.12 GHz. [ABSTRACT FROM AUTHOR]

In the present work, the microstructure modifications and corrosion behaviors of a Mg-4Sm alloy treated by high current pulsed electron beam (HCPEB) with different number of pulses were investigated. The microstructure, composition and phase component in the treated surface layers were characterized by using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) and transmission electron microscope (TEM). The results showed the dissolution of large Mg 41 Sm 5 segregates, the formation of Mg 41 Sm 5 nano-precipitates and twins in the surface layers after treatments. Electrical impedance spectroscopy (EIS) and polarization tests in the 3.5 wt% NaCl solution showed that the 15 pulses treated Mg-4Sm alloy sample exhibited the lowest corrosion current density, highest corrosion potential and polarization resistance among all samples. This is attributed to the homogeneous microstructure and composition with fewer defects in the surface layer after sufficient number of HCPEB pulses. [ABSTRACT FROM AUTHOR]

The microstructures and mechanical properties of as-cast Mg-5Nd- x Al ( x = 0, 0.8, 1.6, 2.4 and 3.0 wt%) were investigated by the optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) and uniaxial tension test. The addition of 3.0 wt% Al led to the most significant grain refinement of Mg-5Nd alloy with the reduction of average grain size from 448 μm to 68 μm. The grain refinement was attributed to the formation of Al 2 Nd particles as the Al 2 Nd particles acted as effective grain refiners for the Mg matrix confirmed by XRD analysis, SEM observation, and crystallography calculation. The mechanical properties of as-cast Mg-5Nd alloy increased obviously after the addition of Al. The yield strength, ultimate tensile strength and elongation of the as-cast Mg-5Nd-3.0Al alloy were enhanced by about 45.3%, 72.4% and 264.0%, respectively, compared to as-cast Mg-5Nd alloy. The improvement of mechanical properties was mainly ascribed to the refined grains and secondary phase strengthening. [ABSTRACT FROM AUTHOR]

Amorphous Al-Ni coating with the Al and Ni mass ratios of 3:2, 3:1 and 4:1 was sprayed on S355 steel of offshore platforms using a laser thermal spraying (LTS). The surface-interface morphologies, chemical element distribution, phase compositions and crystallization temperature of the obtained amorphous Al coatings were analyzed using a scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), and differential scanning calorimetry (DSC), respectively. The immersion corrosion behaviors of the Al-Ni coatings in 3.5% NaCl solution for 720 h were investigated. The results shows that the Al-Ni coating is composed of Al-Fe alloy, AlCrFe 2 , Ni 2 MnAl and amorphous Ni-Mn-Al alloy, the metallurgical bonding is formed at the Al-Ni coating interface due to the diffusions of Al, Ni and Fe elements, and the tensile residual stress induced by LTS accelerated the crack expansion. The amorphous Al-Ni coatings have a certain amount of amorphous component at the crystallization temperature of ∼510 °C. The laser thermal sprayed Al-Ni coating generates the dense oxide film immersed in NaCl solution, hindering the anion from entering, which improving the corrosion resistance of Al-Ni coatings. The electrochemical corrosion resistance of Al-Ni coatings with the Al and Ni mass ratios of 3:2 and 4:1 is better than that with the Al and Ni mass ratio of 3:1, effectively improving the corrosion resistance of S355 steel. [ABSTRACT FROM AUTHOR]

Magnesium and Copper co-doped Zinc oxide nanorods (ZnO NRs) were grown on glass substrates applying hydrothermal technique. They were investigated with respect to their structural and morphological insights through X-ray diffraction (XRD) patterns, field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) technique. The nanorod diameters were found to vary within 105 nm–153 nm. The nanorods were hexagonal in shape with wurtzite structure and oriented along c -axis. Band gap magnitudes were evaluated from the UV–Visible absorption spectra and were found to be higher for Mg5%Cu2%ZnO nanorod sample owing to its smaller crystallite size. Photo-polarization did the additional alignment in the nanorod samples to observe optical nonlinearity of the first and second order. When the spectral energy of the laser beam matched with the energy of the absorption band edge of the samples, we observed also third harmonic generation (THG) besides second harmonic generation (SHG). Quantum chemical calculation using norm-conserving pseudo-potential method was applied to confirm the origin of the effects. [ABSTRACT FROM AUTHOR]

We report herein on the arc erosion behavior of Ti 3 AlC 2 cathode under atmosphere at 7 kV d.c. voltage. The arc life and the breakdown strength for Ti 3 AlC 2 are 28.468 ms and 1.239 × 10 6 V/m, respectively. The process of arc discharging can be divided into three stages: arc formation, steady burning and attenuation, which was observed by a high-speed camera. During steady burning, the arc column is the brightest and the largest. The eroded material was detected by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscope and energy dispersive X-ray spectroscopy. Under the action of arc discharging, the arc erosion morphology characterized with cracks, pores, protrusions with holes displays on the surface of Ti 3 AlC 2 . Meanwhile, the material is dissociated and oxidized to TiO, TiO 2 , Al 2 O 3 , arising from the high temperature and energy intensity of electric arc. The different composition and Marangoni effect are responsible for the multiple morphologies. [ABSTRACT FROM AUTHOR]

Monoclinic Fe 2 (MoO 4 ) 3 thin films have been prepared by chemical spray technique deposited on glass substrates and investigated their physical properties. The obtained thin films were characterized by X-rays diffraction (XRD) using Rietveld's method which confirm the appearance of pure monoclinic Fe 2 (MoO 4 ) 3 thin films. Moreover, the surface morphological was investigated using scanning electron microscope (SEM), which showed the formation of porous microstructures with rough surfaces and spherical nanoparticles. The spectrophotometer UV–Vis–NIR reveals that the sample presents an optical gap equal to 2.0 eV. Electrical properties dependence on both temperature and frequency of the Fe 2 (MoO 4 ) 3 thin films have been reported. The ac conductivity plot showed a universal power law according to the Jonscher model. Activation energy values deduced from the relaxation frequency is of the order of 0.71 eV. Finally, Fe 2 (MoO 4 ) 3 thin films have been tested as sensitive films against ethanol vapor at different operating temperatures and gas concentrations. The films showed promising ethanol sensing behavior with good reproducibility and especially an excellent sensing performance at 275 °C. [ABSTRACT FROM AUTHOR]

The solid state phase equilibria in the Y-Fe-Ga ternary system at 800 °C were investigated by means of X-ray diffraction, scanning electron microscope (SEM) and quantitative electron probe microanalysis (EDS). The isothermal section of the Y-Fe-Ga ternary phase diagram contains 15 single phase-regions, 32 two phase-regions, 12 three phase-regions and one liquid area. The phase diagram at this temperature is characterized by the formation of ten binary stable phases. Among these, there are six extensions of the binary compounds Y 2 Fe 17 , YFe 3 , YFe 2 , YGa 2 , Y 3 Ga 5 and Y 5 Ga 3 into the ternary system Y 2 Fe 17− x Ga x ( x ≤ 2 ), YFe 3− x Ga x ( x ≤ 0.8 ), YFe 2− x Ga x ( x ≤ 0.14 ), YGa 2− x Fe x ( x ≤ 0.5 ), Y 3 Ga 5− x Fe x ( x ≤ 0.15 ) and Y 5 Ga 3− x Fe x ( x ≤ 0.1 ), respectively. The homogeneity range of the YFe 12− x Ga x ternary line compound is between ( 1.5 ≤ x ≤ 9.75 ). [ABSTRACT FROM AUTHOR]

LiFeP 1- x Si x O 4 /(C + y Li 2 SiO 3 ), (0 ≤ x ≤ 0.04, 0 ≤ y ≤ 2%) composites with a particle size of about 200 nm were synthesized via a simple solid state route. In this work, silicon plays double roles-silicon doping in lattice to enhance the electronic conductance of LiFePO 4 , meanwhile Li 2 SiO 3 with high Li-ion conductivity and carbon hybrid coating can decrease the interface resistance between LiFePO 4 grain and electrolyte. In this work, starch and TEOS were used as carbon source and the silicon source respectively. XRD, SEM, TEM, EIS and galvanostatic charge-discharge test are used to characterize these samples. The effects of the modification on the microstructure and electrochemical performances of LiFePO 4 cathodes at 25 °C are systematically investigated. The results show the sample with x = 0.03 and y = 1.0 wt % exhibits excellent rate capacity and cycle performance among the investigated materials. Based on half-cell testing, the best sample achieves a high special discharge capacity of 119 mAh g −1 at 5C rate and a capacity of 94 mAh g −1 at the 10C rate with an excellent cycle life in the usual cycling voltage range 2.5–4.2 V. EIS result demonstrates that the R ct of the samples decrease greatly due to the modification of LiFePO 4 via doping and coating. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of five binary pre-aged Sn-Cu alloys with varying Cu contents were investigated. The Cu compositions examined varied from 1 wt% to 5 wt%. Serial aging heat treatment processes were performed at 373, 393, 413 and 433 K with a holding time of 2 h at each temperature. The microstructural characteristics of the tested alloys have been investigated using scanning electron microscope (SEM) and X-rays diffraction (XRD). Typical indentation creep curves were derived from hardness values. The minimum creep rate is increased as the Cu content increased up to 4 wt%, but above this level the trend is reversed. Moreover, increasing aging temperature resulted in an increase in the minimum creep rate for the all tested alloys. The mean values of energy activating the creep process are in agreement with that quoted for dislocation core diffusion mechanism. [ABSTRACT FROM AUTHOR]

Metal organic framework MIL-101(Cr) nanoparticles were successfully HF- free synthesized via hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Nitrogen adsorption-desorption technology. Then resistive humidity sensor was fabricated to investigate humidity sensing properties. The results indicate that the sensor shows high sensitivity and rapid response-recovery time. The impedance changes more than three orders of magnitude in the range of 33–95% RH at 100 Hz. The response time and recovery time are 17 s and 90 s respectively. Finally, the humidity sensing mechanism was discussed through complex impedance analysis. The results illustrate that porous MIL-101(Cr) nanoparticles have great potential to be used as humidity sensing materials. [ABSTRACT FROM AUTHOR]

Ternary composites of flake shaped carbonyl iron/reduced graphene oxide/polyvinyl pyrrolidone (CI/rGO/PVP) were synthesized via the assembly of positively charged CI and negatively charged graphene oxide (GO) with subsequent chemical reduction and PVP nanoparticles decoration. The preparation of such ternary composites was confirmed by various characterization methods including ξ-potential, scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectrometer (EDS), RAMAN scattering spectroscopy, and X-ray diffraction (XRD). The influence of PVP concentration on the morphology and microwave absorbing property of CI/rGO/PVP composites was studied systematically. The hysteresis loops of pristine flake shaped CI, binary intermediate products and ternary final composites were measured by vibrating sample magnetometer (VSM) to illustrate their statics magnetism characteristics. The microwave absorbing properties of nanocomposites were calculated based on the analysis of electromagnetic parameters measured by vector network analyzer (VNA). According to the relative complex permittivity and relative permeability, dielectric loss of the ternary composites is mainly attributed to the orientational and interfacial polarization, while magnetic loss is prominently ascribed to eddy current loss, natural resonance, exchange resonance and hysteresis loss. The reflection loss (RL) calculation based on transmission line theories demonstrates that as-synthesized composites possess excellent microwave absorbing properties and the product with moderate PVP concentration shows an ultra-wide low reflection (RL < −10 dB) band from 4.2 to 18 GHz with a coating thickness of 2.5 mm. The synergetic effect between dielectric and magnetic constituents with novel ternary nanostructure leads to their enhanced microwave absorbing properties. Furthermore, the addition of rGO with much lower density than CI reduces the density of composites, which makes the CI/rGO/PVP ternary composites a very promising material in microwave absorbing application. [ABSTRACT FROM AUTHOR]

Ti(C, N)-based cermets with different N/(C + N) ratios were prepared by vacuum sintering. The effect of nitrogen content on microstructure of Ti(C, N) based cermets was analyzed using a combination of the electron backscatter diffraction in a scanning electron microscope (EBSD/SEM) and transmission electron microscope (TEM). The combination of XRD and SEM/BSE effectively showed the influence of the carbon and nitrogen contents on the core/rim microstructure features. EBSD maps gave a vivid image for hard phase grains, especially the carbonitride grain size distribution, orientation distribution and crack propagation. The combination of EBSD/SEM and TEM revealed a highly coherent interface between the core and rim. The carbonitride particle and the binder had a large high angle boundary and a coherent interface. A constant interface orientation of the carbonitride particle and binder was characterized. The major factors determining the transverse rupture strength and the fracture toughness were discussed in terms of the crack propagation. [ABSTRACT FROM AUTHOR]

Composite coating of metallic-ceramics tungsten carbide (WC) in nickel matrix has been achieved by direct current (DC) electrodeposition using watt's bath solution on stainless steel substrate. The deposition parameters such as current density, bath temperature, and stirring rate were maintained at constant levels for all the coating configurations. The surface morphologies, microstructure, and chemical composition of the composite coating were studied using scanning electron microscope (SEM), X-ray diffraction (XRD), and energy dispersive analyzer x-ray system (EDX), respectively. The surface morphology and microstructure analysis showed that the composite coatings form cauliflower-like grain colonies, grain size was calculated from Scherrer equation it was less than 60 nm for all composite coating. Micro hardness of composite coating was increased by increasing WC load in solution and decreasing grain size. The electrochemical corrosion behavior of composite coating was evaluated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) in aerated 0.5 mol/l H 2 SO 4 at room temperature, showing passivation behavior of all composite coating, good protection of Ni-8g/l WC on stainless steel substrate. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) has been broadly employed for bone treatment applications. In the present research, HA was extracted from hen, goat and cattle bone. Samples were prepared by cold isostatic pressing method (CIP) and sintered at 1100, 1200 and 1300 °C. In order to evaluate the characteristics of the produced HA, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier Transform spectroscopy (FTIR), scanning electron microcopy (SEM) and energy dispersive spectroscopy (EDS) analyses were carried out on it. Hardness and compression tests were examined before and after sintering. Also, the morphology of the samples at different sintering temperatures was studied by SEM imaging. The obtained experimental results ascertained that with increasing the sintering temperature up to 1300 °C, relative density and hardness of the samples increased. Finally, compressive strength of the sintered sample at 1200 °C was determined as maximum value. [ABSTRACT FROM AUTHOR]

In the present work, the effects of phase constitution on the magnetic and mechanical properties of FeCoNi(CuAl) x ( x = 0–1.2, in molar ratios) high-entropy alloys (HEAs) have been investigated by using vibrating sample magnetometer (VSM), mechanical tester combined with X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and differential scanning calorimeter (DSC). From the experimental results, the crystallographic structures of FeCoNi(CuAl) x HEAs transform from single face-centered cubic (FCC) phase for 0 ≤ x ≤ 0.6 to body-centered cubic (BCC) phase combined with minor FCC phase for 0.9 ≤ x ≤ 1.2, whereas FCC plus BCC duplex phases are found in the range of 0.7 ≤ x < 0.9. TEM images of FeCoNi(CuAl) 0.8 alloy show large numbers of FCC Cu-rich nano-precipitates disperse in the BCC matrix. Furthermore, it is found that the saturation magnetization ( M s ) of HEAs with FCC plus BCC duplex structures abnormally increase with the additions of Cu and Al in contrast to single-phase HEAs, showing a linear decrease in M s . On the other hand, annealing at 573–673 K can lead to a remarkable increase in M s for FCC plus BCC duplex-phase HEAs other than the single-phase HEAs with almost unchanged M s . Specifically, annealing under a given condition can lead to the occurrence of phase transition from FCC to BCC phase for FeCoNi(CuAl) 0.8 HEAs, resulting in a substantial increase in the M s from 78.9 Am 2 /kg to 93.1 Am 2 /kg and yield strength from 536.7 MPa to 1141.1 MPa. The outreach of the present work might provide a promising way to develop HEAs with a combination of superior magnetic and mechanical properties. [ABSTRACT FROM AUTHOR]

The materials LiSrVO 4 (LSV) were successfully synthesized by co-precipitation method varying the concentration of Yb 3+ ions from 0 to 0.01 mol. It was characterize by powder X-ray powder diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infra red (NIR) and ultra violet visible (UV–Vis) region. The Yb 3+ ion doped lithium strontium vanadate (LiSrVO 4 ) phosphors that can convert a photon of UV region (343 nm) into photons of NIR region (988 nm). Hence this phosphor could be used as a quantum cutting (QC) luminescent convertor in front of crystalline silicon solar cell (c-Si) panels to reduce thermalization loss due to spectral mismatch of the solar cells. The theoretical value of quantum efficiency (QE) was calculated from steady time decay measurement and the maximum efficiency approached up to 174.45%. [ABSTRACT FROM AUTHOR]

This work aimed at investigating the superiorities of multilayer graphene (MLG) and β-Si 3 N 4 whisker (β-Si 3 N 4w) in synergistically enhancing the toughness of Si 3 N 4 ceramic composites. First, Si 3 N 4 ceramic composites with hybrid 1 wt% MLG and 0 – 5 wt% β-Si 3 N 4w were sintered by spark plasma sintering. Phase constitutions and microstructures of Si 3 N 4 -based ceramic composites were characterized by X-rays diffraction, Raman spectra, and scanning electron microscope. Then, the optimal β-Si 3 N 4w content and sintering process of MLG/β-Si 3 N 4w -toughened Si 3 N 4 ceramic composites were comprehensively optimized by orthogonal experiments. Results indicated that in the case of maintaining the hardness of 15.87 – 18.84 GPa, the fracture toughness of Si 3 N 4 ceramic composites incorporated with 1 wt% MLG and 3 wt% β-Si 3 N 4w was advanced to 11.04 MPa·m1/2, which was 11.29% and 87.12% higher than that of 1 wt% MLG- and 3 wt% β-Si 3 N 4w -reinforced Si 3 N 4 ceramic composites, respectively. Orthogonal experiments demonstrated that 1 wt% MLG/3 wt% β-Si 3 N 4w -toughened Si 3 N 4 ceramic composites sintered at 1600 ℃, 40 MPa, and holding time for 6 min had optimum comprehensive mechanical properties. MLG wrapping and the synergistic effects of pull out, crack deflection, crack branching, and bridging resulted by MLG and β-Si 3 N 4w were the main responsible for the enhancement of toughness. [Display omitted] • MLG/β-Si 3 N 4w synergistic toughened Si 3 N 4 ceramics were sintered by SPS. • Fracture toughness of Si 3 N 4 -based ceramics was enhanced to 11.04 MPa·m1/2. • Optimal contents of MLG and β-Si 3 N 4w were 1 wt% and 3 wt%. • Optimum sintering process were 1600 ℃, 40 MPa, and holding time for 6 min. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide/copper (rGO/Cu) composites incorporated with nano-SiO 2 particles were successfully fabricated using the raw materials of GO dispersion, hydrophilic nano-SiO 2 and electrolytic Cu powder. The as-prepared composites were characterized by X-ray diffraction, field-emission scanning electron microscope and energy dispersive spectroscopy. Microstructural observation of the composite powders indicated that the graphene oxide (GO) was effectively reduced by N 2 H 4 ·H 2 O addition in the composite slurry, and the nano-SiO 2 particles and rGO sheets were randomly and completely mixed with Cu particles. The as-sintered composites exhibited the small rGO agglomerations in the Cu matrix, and the more nano-SiO 2 additions led to the agglomerations increase. The mechanical property testing revealed that rGO/Cu composites with nano-SiO 2 incorporation exhibited the higher hardness and strength, compared with the rGO/Cu composite and as-cast pure Cu. However, the strengthening in the composites with higher SiO 2 content accompanied with the expense of compressive ductility. Microstructural formation and strengthening mechanism of the composites are also discussed in details. [ABSTRACT FROM AUTHOR]

Undoped and Cr (3% and 5%) doped CdS nanoparticles were synthesized by chemical co-precipitation method. The synthesized nanocrystalline particles are characterized by energy dispersive X-ray analysis (EDAX), scanning electron microscope (SEM), X-ray Diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), Electron paramagnetic resonance (EPR), vibrating sample magnetometer (VSM) and Raman spectroscopy. XRD studies indicate that Cr doping in host CdS result a structural change from Cubic phase to mixed (cubic + hexagonal) phase. Due to quantum confinement effect, widening of the band gap is observed for undoped and Cr doped CdS nanoparticles compared to bulk CdS. The average particle size calculated from band gap values is in good agreement with the TEM study calculation and it is around 4–5 nm. A strong violet emission band consisting of two emission peaks is observed for undoped CdS nanoparticles, whereas for CdS:Cr nanoparticles, a broad emission band ranging from 420 nm to 730 nm with a maximum at ∼587 nm is observed. The broad emission band is due to the overlapped emissions from variety of defects. EPR spectra of CdS:Cr samples reveal resonance signal at g = 2.143 corresponding to interacting Cr 3+ ions. VSM studies indicate that the diamagnetic CdS nanoparticles are transform to ferromagnetic for 3% Cr 3+ doping and the ferromagnetic nature is diminished with increasing the doping concentration to 5%. [ABSTRACT FROM AUTHOR]

Cu-1 wt%Al 2 O 3 composite powder, prepared by mechanical milling and consolidated by spark plasma sintering to have about 98–99% of theoretical density, were characterized by scanning electron microscope, focused ion beam microscope, X-ray diffraction, nanoindentation and transmission electron microscope. The mechanically milled powders, upon consolidation, exhibited a finer grain size of 2 μm. Tensile deformation behavior of this composite, at ambient temperature but over the strain rates of 10 −4 s −1 to 5 × 10 −2 s −1 , exhibited typical manifestations of dynamic strain ageing in the form of serrations and negative strain rate dependence of flow stress. The yield and ultimate tensile strengths, and so also the elongation decrease gradually with increase in strain rate. Such variation was also shown by nanoindentation hardness as a function of loading rate over 1–100 mN/s. The observed results are explained by the dislocation structure evolved from its interaction with Al 2 O 3 dispersoids and impurity atoms like Fe, C and O coming from the powder processing. [ABSTRACT FROM AUTHOR]

The surface of LiNi 1/3 Co 1/3 Mn 1/3 O 2 particles was modified by Li 2 ZrO 3 . Influences of heat-treatment were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The results show that Li 2 ZrO 3 is well-crystallized and successfully coated on the surface of LiNi 1/3 Co 1/3 Mn 1/3 O 2 after heated at 700 °C. Electrochemical tests demonstrate that the coated sample exhibits excellent cycling performances with 89.0% (25 °C) and 84.9% (55 °C) capacity retention at 1C after 100 cycles under the high cut-off voltage of 4.6 V, which are much higher than 82.7% (25 °C) and 62.5% (55 °C) for the pristine one. Meanwhile, the rate capability of the coated sample is dramatically improved even under the high current densities, and the capacities are delivered as high as 168.7 mAh g −1 and 155.2 mAh g −1 at 5C and 10C respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses reveal that coating with Li 2 ZrO 3 could decrease electrode polarization and diminish the charge transfer impedance. Moreover, XRD and SEM characterizations of cycled electrodes evidence that the coating layer of Li 2 ZrO 3 plays an important role in alleviating structural damage of LiNi 1/3 Co 1/3 Mn 1/3 O 2 and protecting LiNi 1/3 Co 1/3 Mn 1/3 O 2 from electrolyte during the charge/discharge processes. [ABSTRACT FROM AUTHOR]

LiNi 1/3 Co 1/3 Mn 1/3 O 2 is successfully coated with MnO 2 by a chemical deposition method. The X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) results demonstrate that MnO 2 forms a thin layer on the surface of LiNi 1/3 Co 1/3 Mn 1/3 O 2 without destroying the crystal structure of the core material. Compared with pristine LiNi 1/3 Co 1/3 Mn 1/3 O 2 , the MnO 2 -coated sample shows enhanced electrochemical performance especially the rate capability. Even at a current density of 750 mA g −1 , the discharge capacity of MnO 2 -coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 is 155.15 mAh g −1 , while that of the pristine electrode is only 132.84 mAh g −1 in the range of 2.5–4.5 V. The cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) curves show that the MnO 2 coating layer reacts with Li + during cycling, which is responsible for the higher discharge capacity of MnO 2 -coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 . Electrochemical impedance spectroscopy (EIS) results confirmed that the MnO 2 coating layer plays an important role in reducing the charge transfer resistance on the electrolyte–electrode interfaces. [ABSTRACT FROM AUTHOR]

Citrated porous PVDF-co-HFP containing LiClO 4 –EC–DEC is prepared with a preferential polymer dissolution process using polyvinyl acetate to create a different porosity ratio of the optimized citrated membrane. All citrated samples (3,5,7,9,11 wt. %) are characterized using X-ray diffraction to show that the sample containing 7 wt. % citric acid has the lowest crystalline structure. The optimized sample is mixed with different PVA concentrations, (4, 8, 12, 16 wt. %), and then all PVA removal copolymer composite samples are immersed in a mixture of a liquid electrolyte containing LiClO 4 , EC, and DEC. The swelling and porosity measurements show that the sample containing 16 wt. % of PVA removal has the highest values, 68% porosity and 115% swelling. Scanning electron microscope is used to show the porous structure of the optimized citrated copolymer electrolyte sample (16 wt. % of PVA removal) compared to the before removing PVA one. DC-electrical conductivity measurement is performed to show the effect of porosity on the conduction process. The sample having 8 wt. % PVA removal shows a high conductivity value of 8 × 10 −4 S cm −1 compared to the other samples at room temperature. Complex impedance, electrochemical stability and stress–strain curve are also studied. All results are collected and discussed. [ABSTRACT FROM AUTHOR]

The effect of YBCO addition on the superconductivity in Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O δ (BSCCO) systems was studied. The samples were prepared through solid state reaction and the properties have been investigated via resistivity measurement ( R – T ), Scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. The highest resistivity measurement was observed for the samples with x = 0.02 of YBCO at 102 K. Generally, all samples exhibit metallic behavior above transition temperature T C onset. From the XRD data, it is observed that the volume percentage of the Bi-2223 phase is initially 75% for the pure samples but decreases till 25% with the increasing Bi-2212 phase. Analysis of the temperature dependence of the AC susceptibility near the transition temperature has been done. The field effect on AC susceptibility was measured. The field increased from 0.05 Oe to 2.00 Oe and the peak temperature ( T P ) gradually decreased to lower temperature from 107.0 K to 108.5 K. [ABSTRACT FROM AUTHOR]

In the current report, Silver doped Zinc Cobaltite (AgZnCo 2 O 4 , AgZCO) nanoparticles have been synthesized through a solvent-free strategy. Synthesized AgZCO nanoparticles were integrated with the reduced graphene oxide (rGO) sheets to prepare the AgZCO@rGO composite. Structural and morphological properties of ZCO, AgZCO, and AgZCO@rGO were studied by various physio-chemical techniques. X-rays diffraction (XRD) analysis showed that all prepared samples possess face-centered cubic crystal structures with crystallite sizes of 5.79 nm, 5.27 nm, and 5.16 nm for ZCO, AgZCO, and AgZCO@rGO, respectively. Scanning electron microscope (SEM) analysis displayed that small spherical nanoparticles of AgZCO were wrapped inside rGO, along with some of the particles present on the surface of rGO sheets. FT-IR characterization showed the presence of all necessary vibrational modes. The results of the photocatalytic experiment showed that 41.97%, 58.02%, and 75.30% MB dye was degraded by the ZCO, AgZCO, and AgZCO@rGO respectively. 65.06% methyl orange dye was degraded by the AgZCO@rGO and it showed the highest percentage degradation with a higher kinetic rate than ZCO and AgZCO catalysts. [Display omitted] • Ag substituted ZnCo 2 O 4 was synthesized by auto-moisturization method. • AgZnCo 2 O 4 nanoparticles were fabricated with rGO sheets. • rGO@ AgZnCo 2 O 4 and AgZnCo 2 O 4 were employed for the degradation of MB dye. • rGO@ AgZnCo 2 O 4 showed superior photo-degradation of MB with 75.30% removal within 105 min [ABSTRACT FROM AUTHOR]

To optimize the mechanical properties of Ti(C,N)-based cermets used as tool materials, the cermets with different Ni–Co binder contents and Co/(Ni + Co) weight ratios were prepared. The effects of metal binder content and Co/(Ni + Co) ratio on the microstructure and mechanical properties of Ti(C,N)-based cermets were investigated by scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and measuring the transverse rupture strength (TRS), Vickers hardness ( HV ) and fracture toughness ( K IC ). The experimental results reveal that increasing Ni–Co binder content can increase the thickness of rim phases by improving the solid solution reaction and the wetting of hard phases. The cermets with 25 wt.% binder addition present good comprehensive mechanical properties, which is attributed to the moderate rim phases and uniformly distributed Ti(C,N) grains. The Co/(Ni + Co) weight ratios in binder have a great influence on the grain sizes and microstructure features of Ti(C,N)-based cermets, in virtue of the synergic effects between the wettability of Co and the solubilizing capacity of Ni on hard phases. The cermets with pure Co as binder exhibit optimal mechanical properties with a TRS of 1767 ± 81 MPa, a hardness of 12.26 ± 0.10 GPa and a K IC of 8.40 ± 0.47 MPa m 1/2 , which meet the requirements for tool materials. And the cermets with a Co/(Ni + Co) ratio of 0.2 have the second best mechanical properties with a TRS of 1848 ± 201 MPa, a hardness of 11.12 ± 0.40 GPa and a K IC of 9.43 ± 0.54 MPa m 1/2 , in which the lower hardness can be further improved by optimizing the compositions and sintering process. [ABSTRACT FROM AUTHOR]

In this paper, Y 3+ ions doped CaMoO 4 :Eu 3+ with controlled microstructures were prepared via a hydrothermal method. All samples were fully characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–vis diffuse reflectance spectroscopy, and photoluminescence measurement. The luminescent performance improvement aroused by doping was systematically investigated after inducing Y 3+ as co-doping ions in CaMoO 4 :Eu 3+ lattice. It is found that the lattice of Y 3+ doped CaMoO 4 :Eu 3+ nanocrystals contracted with increasing the Y 3+ concentration, resulting in a red shift of 1 A 1 → 1 T 1 transition from the valence band to the conduction band. Meanwhile, excitation band at 300 nm corresponding to the typical 1 A 1 → 1 T 1 transition also shifted to lower energy, originating from the charge-transfer between MoO 4 2− group and Eu 3+ ions. When the Y 3+ doping concentration was less than 0.05, the quantum efficiency of Y 3+ doped CaMoO 4 :Eu 3+ nanocrystals was all superior to pure CaMoO 4 :Eu 3+ nanocrystals, which can be assigned to the lattice structure contraction, co-doping effect, doping concentration variation. However, as the content of Y 3+ ions further increasing, Y 3+ ion should act as a luminescence killer, and therefore resulting in a nonradiative de-excitation. [ABSTRACT FROM AUTHOR]

Lead-free and single phase Bi 4− x Sm x Ti 3− x Fe x O 12± δ (0 ⩽ x ⩽ 0.3) ceramics were synthesized using solid state reaction method. Relaxation of distortion in TiO 6 octahedron was confirmed by Raman spectroscopy analysis. The study of surface morphology by field emission scanning electron microscope (FE-SEM) reveals the growth of plate-like grains. Frequency dependent dielectric studies display the reduction of dispersion in both dielectric constant as well as loss tangent with substitution. It is observed that ferroelectric transition temperature ( T c ) of bismuth titanate (BIT) decreases with increasing content of Sm 3+ and Fe 3+ ions. The increase in dc resistivity at room temperature has been found with substitution. A significant improvement in remnant polarization (2 P r ) and magnetization (2 M r ) has been found in the system on substitution. Magnetoelectric coupling coefficient, α = 0.84 mV/cm Oe is realized for x = 0.3 ceramic sample at room temperature. Our results clearly demonstrates the lead-free, multiferroic nature of Sm/Fe substituted BIT, which may find useful application in designing multiple state memory elements, data storage devices and sensors. [ABSTRACT FROM AUTHOR]

A novel and simple method for preparing Mg–50%Al 4 C 3 (hereafter in wt.%) master alloy has been developed by powder in-situ synthesis process under argon atmosphere. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al 4 C 3 particles in this master alloy. After adding 1.8% Mg–50%Al 4 C 3 master alloy, the average grain size of α-Mg decreased from 360 μm to 154 μm. Based on the DTA test results and calculation of the planar disregistry between Al 4 C 3 and α-Mg, Al 4 C 3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase. [ABSTRACT FROM AUTHOR]

Both isothermal and non-isothermal reduction experiments of Panzhihua ilmenite powders by pure hydrogen were carried out using a thermo-gravimetric (TG) analyzer. Results of X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopic (EDS) analyses showed that in the temperature range of 1146–1201 K, the main products were metallic iron, TiO 2 and MgTiO 3 with the iron being embedded in TiO 2 matrix. It was found that the reduction reaction was controlled by the chemical reaction at the reaction interface and the apparent activation energy was extracted to be 98.35–99.02 kJ/mol by using a new kinetic model. However, under the non-isothermal condition, as gradually increasing the temperature to 1493 K, TiO 2 and MgTiO 3 could be reduced, and the final products were metallic iron and Mg x Ti 3 − x O 5 ( x was in the range of 0.45–1). [ABSTRACT FROM AUTHOR]

Spark plasma sintering (SPS) was used to fabricate the Co−Hf−Mo−Ni diffusion multiple in a designed geometry to contain two Co−Hf−Mo and Co−Hf−Ni diffusion triples in one sample, which offers a high-efficiency and low-cost method for preparing this diffusion multiple. In this work, the phase equilibria of the Co−Hf−Mo system at 1373 and 1223 K were established according to the analysis of results obtained using a scanning electron microscope (SEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA) from annealed diffusion triples and equilibrated alloys. The homogeneity range of the ternary compound τ with Hf 9 Mo 4 Co structure was verified in diffusion triples, and solubilities of Mo in Co−Hf, Co in Mo−Hf, and Hf in Co−Mo binary compounds were detected at 1373 and 1223 K. The isothermal sections over the entire composition range at 1373 and 1223 K were successfully constructed. The obtained phase equilibria data provide guidance for the development of multicomponent γ/γ′ Co-based superalloys • Two Co−Hf−Mo and Co−Hf−Ni diffusion triples in one Co−Hf−Mo−Ni diffusion multiple were successfully fabricated by SPS methods. • The composition range of ternary compound τ in the Co−Hf−Mo system was determined at 1373 and 1223 K. • Isothermal sections at 1373 and 1223 K of the Co−Hf−Mo system were constructed. [ABSTRACT FROM AUTHOR]

Multiferroic materials with magnetoelectric coupling have attracted researchers and scientists as these materials can provide higher freedom to facilitate the functioning of multifunctional devices. The three-phase complex multiferroic composites consisting of rhombohedral BiFeO 3 , spinel cubic CoFe 2 O 4 , and tetragonal Pb(Zr 0·52 Ti 0.48)O 3 of the form (1− x) (0.3CoFe 2 O 4 -0.7BiFeO 3)− x Pb(Zr 0·52 Ti 0.48)O 3 (x = 0, 0.1, 0.2, and 0.3) were synthesized following a three-step route. The X-ray diffraction analysis confirmed the respective crystalline phases of the BiFeO 3 , CoFe 2 O 4 , and Pb(Zr 0·52 Ti 0.48)O 3. The Surface microstructures of the composites were analyzed by the scanning electron microscope (SEM) and elemental stoichiometric contents were confirmed by the energy dispersive X-ray (EDX) analysis. Reversible polarization with the application of an applied magnetic field was observed in the form of ME response for all the samples. The electric and magnetic properties (Dielectric, ferroelectric and ferromagnetic properties) were significantly enhanced in the 0.3CoFe 2 O 4 -0.7BiFeO 3 system with the addition of piezoelectric Pb(Zr 0·52 Ti 0.48)O 3 without suppressing their magnetoelectric coupling coefficient (ME), proving the potential of these multiferroic composites for the fabrication of modern devices with multifunctional applications. • Three-phase multiferroic composites were synthesized following a three-step route. • X-ray diffraction analysis confirmed the respective three crystalline phases. • Elemental presence and stoichiometric contents were confirmed using EDX analysis. • Dielectric, ferroelectric and ferromagnetic properties were significantly enhanced. • The electronic properties improved without suppressing ME coupling coefficient. [ABSTRACT FROM AUTHOR]

The chemically architectured alloys were proposed as a new concept of microstructure, with a multi-scale architecturation. They are composed of a solid-solution at the atomic scale, grain boundaries and composition gradients at the micronic scale and finally a 3D network of gradients at the mesoscale. Composition gradients are between two phases with the same crystalline structure but different compositions. As a first application of this concept, powders of pure Ni and CoCrFeMnNi high entropy alloy were successfully densified by Spark Plasma Sintering. Then the microstructure and mechanical properties were characterized by scanning electron microscope coupled with energy dispersive spectroscopy and electron backscattered diffraction, X-ray diffraction, nanoindentation and compression tests. The obtained chemically architectured alloys present a homogeneous distribution of the two phases with a 10 μm wide chemical gradient in between. By comparison with reference non architectured materials, the chemical architecturation induces a 35% increase of the yield strength. Thus the concept of chemically architectured metallic alloys and composition gradients was proven as very promising: processing of this complex microstructure is possible and it induces a significant mechanical strengthening. Image 1 • A mixture of CoCrFeMnNi and Ni powders was fully densified by spark plasma sintering. • A chemical gradient of around 10 μm was formed between HEA and Ni phases. • This material is called a chemically architectured alloy. • Mechanical strength is improved compared to an ideal mixture of Ni and CoCrFeMnNi. [ABSTRACT FROM AUTHOR]