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A series of Bi 0.48 (Na 0.84 K 0.16) 0.48 Sr 0.04 (Ti 1- x Ta x)O 3 (abbreviated as NKS-100 x Ta) lead-free piezoelectric ceramics were fabricated using a traditional solid-state method. The structure and electrical properties of NKS-100 x Ta were investigated in detail. The composition for x = 0.01 presented an enhanced electric field induced bipolar strain of ∼0.53%, as well as the giant unipolar strain of ∼0.478% corresponding to S max / E max ∼682 p.m./V at 70 kV/cm. It is found that the ferroelectric-relaxor transition temperature (T F-R) shifted down to ambient temperature and the remnant polarization (P r) decreased with the Ta doping. It destroyed the long-range ferroelectric ordering and increased the relaxor characteristic. Therefore, the origin of giant strain was ascribed to the transformation from the ferroelectric phase to relaxor phase under the applied electric field. In addition, the well fatigue properties within 104 cycles indicated that the prepared ceramics offered extendable availability for sensors and actuators. Fig. 5. (a) Unipolar strain curves of the NKS-100 x Ta measured at 70 kV/cm with 1 Hz frequency. (b) P r , P m and d * 33 as a function of Ta content. Image 1 • A ferroelectric-to-relaxor transition is obtained by chemical modification. • The giant unipolar strain of 0.478% corresponding to S max / E max ∼ 682 pm/V at 70 kV/cm obtained at ambient temperature. • The giant strain derives from the combination of interior and extrinsic effects. [ABSTRACT FROM AUTHOR]

New ferromagnetic (Fe 1/3 Co 1/3 Ni 1/3) 80 (P 1/2 B 1/2) 20 high entropy bulk metallic glass (HE-BMG) with the maximum diameter of 2 mm has been prepared by combining fluxing treatment and J-quenching technique. The present HE-BMG exhibits excellent soft magnetic properties with a saturation magnetization of 0.90 T, low coercivity of 1.5 A/m, high permeability of 10172 @ 1 kHz and low hysteresis loss of 21 kJ/mol @ 50 Hz (for the annealed glassy ribbon), and mechanical properties with a compressive yield strength of 3000 MPa and large plastic strain of 4%. The combination of superior glass-forming ability, excellent magnetic and mechanical properties makes the present HE-BMG a future promising application as advanced structural and functional materials. • (Fe 1/3 Co 1/3 Ni 1/3) 80 (P 1/2 B 1/2) 20 high entropy bulk metallic glass was prepared by fluxing treatment and J-quenching technique. • The critical diameter of (Fe 1/3 Co 1/3 Ni 1/3) 80 (P 1/2 B 1/2) 20 high entropy bulk metallic glass reaches to 2 mm. • (Fe 1/3 Co 1/3 Ni 1/3) 80 (P 1/2 B 1/2) 20 high entropy bulk metallic glass exhibits the strength of 3.0 GPa and plastic strain of 4%. • (Fe 1/3 Co 1/3 Ni 1/3) 80 (P 1/2 B 1/2) 20 high entropy bulk metallic glass exhibits a high saturation magnetization of 0.9 T. [ABSTRACT FROM AUTHOR]

Abstract Relatively high strength and good ductility are rarely obtained simultaneously in aluminum matrix composites. In the present work, dual-phased TiC n -Al 3 Ti m (n: nanosized TiC particles and m: micron-sized Al 3 Ti particles) particles were in situ synthesized in an Al-Ti-C system via the combustion synthesis method. Subsequently, (TiC n -Al 3 Ti m)/Al hybrid composites were readily fabricated at high addition levels (0, 1, 3, 5 and 7 vol%) via the re-melting and diluting method assisted ultrasonic vibration. Then, the isolated influences of the dual-phased TiC n -Al 3 Ti m particles on the solidification behaviors, microstructure evolution and mechanical properties, at both ambient- and elevated-temperatures, of aluminum alloys were systematically investigated. The experimental results revealed that the α-Al dendrites were substantially refined with a reduction of up to 4 times when compared with that of the unreinforced base alloy. Furthermore, at ambient temperature, 5 vol% (TiC n -Al 3 Ti m)/Al exhibited the optimum comprehensive mechanical properties, and the yield and ultimate tensile strength were 124.3% and 165.2% higher than those of the unreinforced base alloy, whilst the fracture strain was not sacrificed. Theoretical calculations suggest that thermal-mismatch and Orowan strengthening effects contributed most to the yield strength increment, whereas the favourable fracture strain was achieved mainly due to grain refinement. Moreover, at elevated temperature (453 K), the yield strength and ultimate tensile strength were improved by 327.8% and 236.1%, respectively, whilst the fracture strain was still at a relatively high level of 29.2%. The improved thermal resistance primarily resulted from the pinning effects of the TiC n -Al 3 Ti m particles on the grain boundaries and dislocations. Highlights • Novel dual-phased TiC n -Al 3 Ti m particles were in situ synthesized. • TiC n -Al 3 Ti m exerted refinement by heterogeneous nucleation and inhibited growth. • TiC n -Al 3 Ti m enhanced strength at 298 K by thermal mismatch and Orowan effects. • TiC n -Al 3 Ti m enhanced strength at 453 K by pinning and retarding effects. [ABSTRACT FROM AUTHOR]

Abstract Leed-free ferroelectric (1-x)(0.72Bi 0.5 Na 0.5 TiO 3 -0.28Bi 0.2 Sr 0.7□0.1 TiO 3)-xLa (NBST-xLa; x = 0, 0.5%, 1.5%, 2%) ceramics were synthesized using a conventional solid-state reaction method and the effect of La-doping on the microstructure and electrical properties was investigated. The introduction of La could reduce the grain size and improve the porosity of NBST ceramics. Temperature-dependent dielectric permittivity illustrated that the relaxation properties of NBST-xLa ceramics changed parabolically with the increase of La content. The introduction of La gave rise to a large dielectric breakdown strength and maximum polarization when x = 0.5%, which was attributed to the variation of the microstructure and the relaxation properties of NBST-xLa ceramics, respectively. The optimum effective energy storage density of 1.2 J/cm3 at 90 kV/cm was achieved when x = 0.5%. These results indicated that NBST-0.5%La ceramic may provide a practical perspective for energy storage ceramics research. Highlights • La-doped ceramics were synthesized using a solid-state reaction method. • The introduction of La gave rise to a large DBS and P max. • NBST-0.5%La possessed the optimum effective energy storage density. [ABSTRACT FROM AUTHOR]

Abstract Noble-metal Au nanoparticles decorated InP nanopore arrays have been synthesized via a facile impregnation-deposition method. The morphology and element composition of the resulting Au@InP composite samples were characterized by X-ray diffractometry (XRD), field-emission scanning electron microscopy, X-ray photoelectron spectroscopy. The as-obtained Au@InP nanoarray exhibits promising behavior in photoelectrochemical hydrogen production, giving rise to a dramatically enhanced photocurrent density and onset potential, much superior to that of pristine InP nanopore arrays. Density functional theory (DFT) calculation reveals that the enhanced PEC performance can be attributed to the reduced recombination of electron-hole pairs. Therefore, this work supplies an effective way for the construction of metal/semiconductor nanoarrays, which can be potentially used in the energy storage and conversion field. Graphical abstract Image 1 Highlights • Au@InP nanopore arrays are fabricated via facile and cost-effective method. • Au@InP largely enhance photoelectrochemical (PEC) H 2 production compared to pure InP. • The improved PEC performance can be attributed to the enhanced charge separation. [ABSTRACT FROM AUTHOR]

Radial electric ( E )-field induced periodic polarization rotation from orthorhombic (O) to M C -type monoclinic (M C ) phase in Pb(Mg 1/3 Nb 2/3 )O 3 -0.34PbTiO 3 (PMN-0.34 PT) single crystals has been studied by in situ polarized light microscope. The piezoelectric coefficient ( d 33 ∗ ) and dielectric permittivity ( ε 33 T / ε 0 ) were 1800 pm/V and 5100, respectively, for [100]-oriented M C samples, almost three times of those in [011]-oriented O phase crystals. The domain structure evolution from 1O to 4M C was confirmed based on the optical extinction rules and permissible domain configurations. Moreover, the phase transition sequences of [100]- and [011]-poled PMN-0.34 PT crystals were M C —Tetragonal (T)—Cubic (C) and O—T—C upon heating, respectively. Our findings suggest that the phase stability of this crystals is associated with the orientation of applied field and radial E- field can serve as a general strategy to get fundamental insights into large piezoelectric activity and anisotropic phase stability in ferroelectric single crystals. [ABSTRACT FROM AUTHOR]

Here, we report the scalable preparation of Pt nanoparticles decorated indium phosphide nanopore arrays (Pt@InP NPAs) using a facile two-step etching method followed by a dipping and electrodeposition process. The morphology and element composition of the Pt@InP heterostructures were characterized. Photoelectrochemical properties of the Pt@InP electrodes were investigated under simulated sunlight irradiation. Compared to pristine InP NPAs, the resulting Pt@InP NPAs show a greatly increased photocurrent density and a largely improved onset potential for photoelectrochemical (PEC) hydrogen evolution. Electrochemical impedance spectroscopy reveals that the improved PEC performance is attributed to the enhanced charge transfer and the improved charge separation at Pt@InP NPAs/electrolyte interfaces. [ABSTRACT FROM AUTHOR]

In this paper we report BiFeO 3 -Bi 2 Fe 4 O 9 composite with negative permittivity at about 1 GHz, a necessary step to construct a real metamaterial with both negative permeability and negative permittivity. This purposely designed material is obtained by a self-assembly procedure with the same starting raw material. The composite material shows a dielectric resonance at about 1 GHz. The reason for the resonance is analyzed, based on the equivalent resistance-inductance-capacitance circuit, which is confirmed through the theoretical model. Furthermore, the frequency of the resonance can be easily tuned by varying the composition ratio. Our results show that the composite is applicable in the new field of metamaterials for the miniaturization of antennas. [ABSTRACT FROM AUTHOR]

Multiferroic Bi 1−x Sm x FeO 3 (x = 0.00–0.05) ceramics were prepared by a conventional solid-state reaction method, and effects of Sm 3+ ions on crystal structure, magnetic and dielectric properties were investigated. TGA-DSC studied the synthesis process of pure BiFeO 3 sample and confirmed the synthesis temperature was about 825 °C. For all samples, they were rhombohedral distorted perovskite structure of R-3c space group. Lattice constants and particle sizes decreased based on the data of XRD and Rietveld refinement. Morphologies of the samples were determined with Scanning Electron Microscopy proving the grain to be shrinkage. With increasing of Sm 3+ ions, saturation magnetization of Bi 0.97 Sm 0.03 FeO 3 material at 5000 Oe was about 1.5 times larger than that of pure BiFeO 3 , while the coercivity increased from 87.3 Oe to 121.3 Oe. In a wide range frequency from 1 MHz to 1.6 GHz, dielectric constant kept a stable value. With Sm 3+ increasing, dielectric constant increased from 27 to 46, while dielectric loss kept a low value. [ABSTRACT FROM AUTHOR]

The development of lead-free ceramics with high energy storage density is critical due to the human health and environmental hazards of lead and the demand to miniaturize and integrate electronic devices. Nevertheless, the high applied electric field limits their use in integrated circuits. In this work, (1- x) Bi 0.5 (Na 0.82 K 0.18) 0.5 Ti 0.99 (Y 0.5 Nb 0.5) 0.01 O 3 - x NaNbO 3 (BNKTYN-100 x NN) ceramics were prepared, and excellent energy storage properties were obtained. It has revealed that NaNbO 3 dopant reduces remanent polarization and increases relaxor degree. BNKTYN-9NN ceramics has high energy storage density (W rec =1.6 J/cm3) and responsivity (ξ = W rec / E = 145.5 J/(kV•m2)) under 110 kV/cm. Meanwhile, good temperature stability (20–120 °C) and fatigue resistance (105 cycles) were also obtained in BNKTYN-9NN ceramics. In addition, doping NaNbO 3 suppresses the dielectric anomaly peak, and BNKTYN-9NN ceramics has excellent temperature-stable dielectric permittivity from 53° to 447°C. These results suggest that BNKTYN-100 x NN ceramics are promising for energy storage equipment. • Using antiferroelectric NaNbO 3 to improve the energy storage performance of Bi 0.5 (Na 0.82 K 0.18) 0.5 TiO 3 -based ceramics. • A high W rec of 1.6 J/cm3 and η of 73.1 % at a lower electric field of 110 kV/cm were obtained in the x = 0.09 composition. • BNKTYN-9NN ceramics has outstanding dielectric temperature stability from 53 °C to 447 °C. [ABSTRACT FROM AUTHOR]

Lead-free (1- x)[(Bi 0.5 Na 0.5) 0.94 Ba 0.06 TiO 3 ]- x AgNbO 3 (abbreviated as BNTBT-100 x AN) ceramics were fabricated using a conventional solid-phase reaction technique. The effect of the antiferroelectric AgNbO 3 dopants for fatigue resistance, energy-storage density, temperature-stable permittivity, and conductivity mechanism was systematically investigated. The addition of AgNbO 3 led to the decrease of remnant polarization and the increase of dielectric breakdown strength, a large effective energy-storage density of ~1.27 J/cm3 corresponding to the conversion efficiency of ~ 77.5% for BNTBT-5AN ceramic were attained under applied 105 kV/cm field. Meanwhile, it exhibited an outstanding fatigue-resistant performance at 70 kV/cm fixed field up to 105 cycles accompanied with excellent temperature-stable properties in the temperature range of 30 °C ~ 120 °C. Besides, BNTBT-5AN sample has also obtained outstanding temperature-stable permittivity, which was associated with the enhancement of the ergodic relaxor domain structure. A little variance of dielectric content (Δ ε' / ε' 150 °C ≤ ± 15%) was acquired from 40 °C to 387 °C with a small tangent loss (tan δ ≤ 0.05) between 50 °C and 461 °C. Hence, it revealed that the high energy storage properties and excellent dielectric temperature stability for BNTBT-5AN ceramic were conducive to its better applications in electronic equipment. • A large effective energy-storage density of ~ 1.27 J/cm3 corresponding to the conversion efficiency of ~ 77.5% for x = 0.05 composition were attained under applied 105 kV/cm field. • BNTBT-5AN ceramic has also obtained outstanding temperature-stable permittivity, which was associated with the enhancement of the ergodic relaxor domain structure. • A little variance of dielectric content (Δ ε' / ε' 150 °C ≤ ± 15%) was acquired from 40 to 387 °C with a small tangent less (tan δ ≤ 0.05) between 50 °C and 461 °C for BNTBT-5AN ceramic. [ABSTRACT FROM AUTHOR]

The 0.94Bi 0.5 Na 0.5 TiO 3 –0.06BaTiO 3 (BNBT6) introduced by CaZrO 3 (CZ) lead-free ferroelectric ceramics are successfully fabricated by conventional solid state reaction. The influence of CZ substitution on the phase transition, microstructure, dielectric, ferroelectric, and energy storage properties of (1 − x)BNBT6-xCZ ceramics are systematically investigated. The energy-storage density 0.7 J/cm 3 under the electric field 70 kV/cm is obtained in the 0.97BNBT6-0.03CZ. In addition, its energy-storage property exhibits thermal stability at the temperature range of 30–130 °C. [ABSTRACT FROM AUTHOR]

M-type barium hexaferrite (BaM) thin films with different structures ( d s100 : single-layer 100 nm thick film; d s200 : single-layer 200 nm thick film; d b200 : bilayer 200 nm thick film, where the thickness of each layer is 100 nm and the total film thickness is 200 nm) were deposited on (001) sapphire (Al 2 O 3 ) substrate by radio frequency (RF) magnetron sputtering. Effects of different structures on the crystallographic, morphological, magnetic properties and stress were investigated in details. For the structure of d s100 , BaM film processes platelet-like grains, which shows excellent magnetocrystalline anisotropy and large squareness ratio S ⊥ (0.62). For the structure of d s200 , there are a lot of acicular grains. Thus, the c-axis in-plane oriented and/or randomly oriented grains induce poor magnetocrystalline anisotropy. For the structure of d b200 , the platelet-like grains dominate the microstructure. Both squareness ratio S ⊥ (0.67) and coercivity H c⊥ (98.6 kA/m) of the d b200 show the highest values among the three kinds of the film structures. In addition, with the increase of film thickness from 100 nm to 200 nm, the stress in film decreases gradually. Compared with the other structures, the bilayer 200 nm thick film ( d b200 ) obtains the smallest stress. [ABSTRACT FROM AUTHOR]

Fully epitaxial FeCo/MgO/Fe magnetic tunnel junctions on silicon substrates were fabricated using in situ shadow-masks in an electron-beam deposition system. An inverse tunneling magnetoresistance (TMR) of −39% was observed at 77 K after annealing, which was not obtained in MTJs grown in better vacuum with the same device structure. This inverse TMR is attributed to the oxidation of the FeCo/MgO interface, which provides a negative spin polarization. Our work highlights the importance of interfacial properties on tunneling magnetoresistance and points to a simple processing route to achieve inverse TMR by carefully controlling the oxidation condition of the bottom layer. [ABSTRACT FROM AUTHOR]

The current study investigates the effect of strong magnetic field on the micro-structure of pure diopside and diopside doped with Fe 3+ or Mn 2+ . The microstructure changes were characterized by X-ray diffraction (XRD), UV–vis, and Raman spectroscopy. The results of XRD show that the strong magnetic field can increase the peak height of (311) diffraction and the height ratio of (310)/(311) is proportional to the strength of the magnetic field. UV–vis results show that the magnetic treatment and the transition-metal ion doping have some influences on the light absorbance of the diopside samples. With a fixed doping concentration, the UV–Vis absorbance of Fe 3+ -doped samples decreased after magnetic treatments, however, same UV–Vis absorbance increased for the Mn 2+ -doped samples. Result from Raman spectra suggests that Raman shift of the maximum peak value changed from 671 cm −1 before the magnetic treatment to 1015 cm −1 after the magnetic treatment. Meanwhile, the Raman intensities at 330 cm −1 and 395 cm −1 become more obvious after the magnetic treatment. The results of this study indicate a minor change in the relative positions among the ions, which then leads to polarizability changes. [ABSTRACT FROM AUTHOR]

In this article, high-quality single domain SmBCO bulks have been successfully produced in the air by top seeded infiltration and growth (TSIG) method, with a new solid phase of (Sm 2 O 3 + xBaCuO 2 ) and liquid phase of (Y 2 O 3 + 6CuO + 10BaCuO 2 ), x = 0.9, 1.0, 1.1, 1.2, 1.3 and 1.4. The results show that the onset critical temperature (T c-onset ) of the SmBCO bulks increases with the increasing of x, because the substitution of Sm on Ba site in Sm 1+x Ba 2−x Cu 3 O 7 crystal is reduced by the BaCuO 2 addition; the T c-onset have reached 96 K when x = 1.4. The amount and the size of Sm211 particles of the single domain SmBCO bulks decreases with the increasing of BaCuO 2 addition x. All of the critical current density (J c ), levitation force and trapped field of the samples are increasing from 1.08 × 10 5 A/cm 2 , 38.47 N and 0.2330 T to 1.66 × 10 5 A/cm 2 , 44.34 N and 0.2680 T when x increases from 0.9 to 1.2, and then decreases to 0.83 × 10 5 A/cm 2 , 37.94 N and 0.2085 T with the increasing of x from 1.2 to 1.4 respectively, the largest J c of 1.66 × 10 5 A/cm 2 , levitation force of 44.34 N and trapped field of 0.2680 T are reached at the optimal value of x = 1.2. This result provides a very important way to fabricate high-quality single domain SmBCO bulks in air. [ABSTRACT FROM AUTHOR]

Hot deformation behavior of Cu-0.36Cr-0.03Zr alloy is investigated by hot compression tests in a wide range of temperatures (800, 900, 950 °C) and strain rates (0.001, 0.01, 0.1, 1, 10, 20 s −1 ). For eliminating friction effects during tests and adiabatic effects at high strain rates, true stress–strain curves are friction corrected and then temperature corrected to elucidate real hot deformation behavior. True stress–strain curves after correction exhibit typical characteristics of dynamic recovery and dynamic recrystallization. The deformation activation energy of this alloy under this test condition is calculated as 432.6 KJ/Mol. Based on the stress–dislocation relation and kinetics of dynamic recrystallization, a physically-based constitutive model is developed. The predicted stresses agree well with experimental ones with the correlation coefficient (R) of 0.9982 and the average absolute relative error (AARE) of 3.47%. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermochromic coatings were synthesized by plasma spraying method. [•] The coating exhibits a metal–insulator transition. [•] Emissivity increment of the coating at 97–373K is 0.33. [•] Large solar absorptivity of the coating is reported. [ABSTRACT FROM AUTHOR]

Highlights: [•] N–Co-codoped TiO2 was prepared by hydrothermal method at vapor–liquid interface. [•] Hierarchical N–Co-codoped TiO2 was synthesized. [•] Growth mechanism of N–Co-codoped TiO2 was discussed. [•] Ferromagnetism was found on the titanate N–Co-codoped TiO2 at room temperature. [•] Light absorption edge of N–Co-codoped TiO2 was shifted to visible light region. [Copyright &y& Elsevier]

Highlights: [•] Cu1.75S NCs play the catalytic roles for the growth of the CuGaS2 nanoribbon. [•] During the growth of CuGaS2 nanoribbon, Cu1.75S NCs were consumed gradually. [•] Photoresponse of CuGaS2 thin film shows 17-fold increase from dark to illumination. [Copyright &y& Elsevier]

Abstract: By controlling the deposition rate of Zn atoms, we simultaneously synthesized ZnO particles on the upper surface of a horizontal silicon substrate, and ZnO rods array on its lower surface via a thermal evaporation process. The deposition rate of Zn atoms not only affects the morphologies of the final ZnO products, but also consequently leads to ZnO particles and ZnO rods array that have different photoluminescence properties and wetting behaviors. These two morphological ZnO products have just opposite relative intensities of UV emission to visible emission. ZnO rods array has a water contact angle of 160.3°, while ZnO particles film has a water contact angle of 150.4°, and their wetting behavior changed from the Cassie state to the Wenzel state during the process of droplet evaporation. [Copyright &y& Elsevier]

• The doping of Li+ ion has an obvious influence on the strain and energy storage performance. • The TEM image and XPS spectra of O 1s for BNKTT-100xLi ceramics demonstrate the existence of PNRs and oxygen vacancies. • The maximum bipolar strain (S = 0.462%) and unipolar strain (S u = 0.443%) for x = 0.025 sample were obtained under 80 kV/cm, and its unipolar strain achieved 0.573% at 100 °C. • BNKTT-15Li ceramic exhibited outstanding energy storage performance with a recoverable energy density of 1.29 J/cm3 under applied 130 kV/cm field. The conventional solid reaction was used to synthesize (Na 0.8- x K 0.2 Li x) 0.5 Bi 0.5 Ti 0.985 Ta 0.015 O 3 (abbreviated as BNKTT-100 x Li) lead-free perovskite ceramics. The influences of Li+ ion doping for the relaxation mechanism and piezoelectric performances of all ceramics were systematically investigated. All ceramics exhibited a single perovskite structure, accompanied with a dense surface morphology and uniform element distributions. AC impedance spectroscopy showed the single grain conduction mechanism for all samples. The maximum bipolar strain (S = 0.462%) and unipolar strain (S u = 0.443%) for x = 0.025 sample were obtained under 80 kV/cm, and its unipolar strain achieved 0.573% at 100 °C. BNKTT-15Li ceramic exhibited outstanding energy storage performance with a recoverable energy density of 1.29 J/cm3 under applied 130 kV/cm field. It suggested that the excellent electro-strain and energy-storage properties for BNKTT-100 x Li ceramics could be widely applicable to electronic equipment. [ABSTRACT FROM AUTHOR]

Abstract: Mono-disperse Ni0.5Zn0.5Fe2O4 spinel ferrite particles have been synthesized directly via the hydrothermal method using sodium dodecyl sulfate (SDS) as surfactant. Particle size could be varied from 6 to 19nm by changing the experiment parameters. X-ray diffraction, high resolution TEM images confirmed the high crystallinity of ferrite nanocrystals. The effects of precursor suspension pH value, reaction temperature and surfactant (SDS) concentration on phase purity, particle size and dispersed property were discussed. The results indicated that mono-disperse Ni0.5Zn0.5Fe2O4 spinel ferrite nanoparticle had been obtained at pH value range (8–9), reaction temperature (90°C) and moderate SDS concentration (>0.2mM). The magnetic measurement shows that as prepared Ni0.5Zn0.5Fe2O4 nanoparticle possesses good super-paramagnetic behavior. We also put forward a primary experimental model to shed light on the controllability of the monodispersity of the nanosized particles. [Copyright &y& Elsevier]

Abstract: Direct chill cast Mg–Zn–Zr alloys with different amount of Nd and Y additions have been investigated in this study. The interdendritic phases of as-cast Mg–5Zn–0.6Zr alloy were comprised of a small amount of Zn2Zr3 and Mg4Zn7. They were changed by the addition of Nd to T phase or T phase coexisting with W phase, and the additions of Nd and Y to W phase, occurring with a refinement of dendritic size, an increase of interdendritic phase amount and an improvement in the thermal stability of interdendritic phases. There was a strong dependence of tensile properties on microstructure. The continuous networks of intergranular phases in Mg–Zn–Nd–Zr alloys significantly deteriorated the ultimate strength and elongation, whereas the less continuity of intergranular phases in the Mg–Zn–Nd–Y–Zr alloys favored the ultimate strength and elongation. [Copyright &y& Elsevier]

Abstract: Nano-scaled aluminum yttrium garnet (YAG) powders with a spherical morphology were prepared by a mixed-solvo-thermal method under moderate reaction conditions using inexpensive starting materials. The effects of the changing process parameters on phase evolution, constitute and morphology of the resulting samples were characterized by X-ray diffraction (XRD), DTA–TG, transmission electronic microscope (TEM) and HRTEM techniques. The results show that pure phase YAG powders can be successfully synthesized at 300°C for 1h when the volume ratio of ethanol to water is 2 or larger. The TEM results reveal that the YAG particles synthesized are well-dispersed fine spherical grains with a relatively narrow grain size distribution. Finally, the formation mechanism for solvo-thermal crystallization of YAG grains is proposed based on IR results. [Copyright &y& Elsevier]

Electrode materials with optimized structure and electrocatalyst utilization can promote the progress of high-performance Li-O 2 batteries (LOBs). Herein, the catalyst was synthesized by in situ growing RuO 2 nanoparticles on metal-organic frameworks (MOFs) derived carbonaceous polyhedrons co-doped with cobalt and nitrogen (Co-N-C). The porous composition of the Co-N-C facilitated O 2 and Li+ diffusion and provided adequate space for storage of discharged products. Furthermore, the RuO 2 catalyst facilitated a process that reversed of Li 2 O 2 accumulation and decomposition on the positive electrode surface. The LOBs with this innovative catalyst exhibited a notable discharge capacity (16671 mAh g−1) and displayed extended cyclability (174 cycles) under 200 mA g−1.In addition, the density functional theory (DFT) simulations reveal that the RuO 2 /Co-N-C offer high catalytic activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Hence, the present work introduces a potential approach to designing electrocatalysts that exhibit great efficiency and promise for use in high-performance LOBs. • Optimizing electrodes and catalysts boosts Li-O 2 battery performance. • New RuO 2 nanoparticle catalysts from Co/N-doped MOF derivatives. • Catalyst enhances battery with better O 2 /Li+ diffusion and storage space. • Catalyst reverses Li 2 O 2 buildup and decomposition on positive electrode. [ABSTRACT FROM AUTHOR]

The Sn-doped Bi 0.5 Sr 0.5 FeO 3- δ (BSF)-based perovskite oxide is evaluated as novel cathode electrocatalyst for intermediate-temperature solid oxide fuel cells (IT-SOFCs). In particular, the effects of 10 mol% Sn substitution on phase evolution, thermal expansion behavior and electrochemical performance of Bi 0.5 Sr 0.5 Fe 0.9 Sn 0.1 O 3- δ (BSFSn) material are systematically investigated. BSFSn crystallizes in cubic perovskite structure with space group P m-3m. Sn doping is found to decrease the average thermal expansion coefficient (TEC) from 14.7 × 10−6 K−1 (BSF) to 12.9 × 10−6 K−1 (BSFSn) within a temperature range of 50–800 °C, due to the enlarged metal-oxygen (Sn-O) bond energy in BSFSn. The X-ray photoelectron spectroscopy (XPS) result proves that Sn doping promotes the oxygen adsorption ability on BSFSn surface. Consequently, the ORR activity of BSFSn is improved as expected. The polarization resistance (R p) value of BSFSn cathode is 0.09 Ω cm2 at 700 °C in air, which is lower than BSF. The cathode overpotential is 35.6 mV at a current density of 140.8 mA cm−2 at 700 °C in air. The peak power density of the anode-supported cell reaches 960 mW cm−2 at 700 °C. Furthermore, the relationship between oxygen partial pressure and R p demonstrates that oxygen surface adsorption-desorption is a major rate-limiting step for oxygen reduction reaction (ORR) process on BSFSn cathode. These attractive electrochemical properties suggest that BSFSn oxide is a promising potential cathode electrocatalyst for SOFCs. Image 1 • Bi 0.5 Sr 0.5 Fe 0.9 Sn 0.1 O 3- δ electrocatalyst is evaluated for application in SOFCs. • Cathode material gave the lower polarization resistance of 0.09 Ω cm2 at 700 °C. • The rate-limiting step of ORR is oxygen adsorption-dissociation process. [ABSTRACT FROM AUTHOR]

Abstract: Al-doped zinc oxide (AZO) thin films have been prepared by pulsed laser deposition. AZO films were observed to grow along the c-axis orientation of (002). Optical and photoluminescent properties of the AZO films have been investigated. The UV absorption edge was blue shifted with increasing Al doping concentration. AZO films with different Al contents observe only ultraviolet emission without notable DLEs. All films have an average optical transparency over 80% in the visible range. The possible origins responsible for these emission bands have been discussed. [Copyright &y& Elsevier]

3D porous flower-like ZnO microstructures loaded by large-size Ag were successfully synthesized via a simple two-stage method. XRD and XPS results proved that the synthesized Ag/ZnO was a pure phase. SEM and TEM results showed that the Ag nanoparticles with large size (about 400 nm) were successfully loaded on the porous flower-like ZnO. The sensitivity of Ag/ZnO was 268 to 200 ppm ethanol at 300 °C, which was 6 times higher than that of pure ZnO. In addition, the sensor of Ag/ZnO exhibited a faster response/recovery behavior and a lower detection limit. The enhanced gas sensing performance of Ag/ZnO has been explained from three aspects: the "spillover effect" of Ag, the formation of metal-semiconductor heterojunction and the role of "electronic sensitization". • A new method to synthesize large-size Ag nanoparticles (400 nm) and loaded it on 3D porous flower-like ZnO. • Ag/ZnO gas sensor displays higher gas response and faster response/recover time. • This paper explains the enhanced gas sensing mechanism from three aspects. [ABSTRACT FROM AUTHOR]

In this paper, double negative performance of GdFeO 3 in GHz range was investigated. Double negative performance generally occurs in ceramic/metal composites or artificial metamaterials. Therefore, this behavior of single phase ABO 3 perovskites is very interesting. Conventional solid phase method was used for synthesis of GdFeO 3 ceramics. Double negative performance of GdFeO 3 occurred, with negative permeability at 2.6–2.8 GHz and negative permittivity at 0.9–1.4 GHz. The reason for the resonance was also analyzed. Furthermore, resonance frequency could be easily adjusted by varying sintering temperature. Results showed that GdFeO 3 can be applied in new field of metamaterials for antennas. By placing a double negative metamaterial lens in front of antenna source, the gain and directivity of the antenna can be increased. The material can be placed in front of antenna source as a zero-refractive metamaterial lens. Therefore, it is necessary to study the properties of metamaterials based on GdFeO 3. • GdFeO 3 exhibits double negative performance in the GHz range. • The resonance frequency of GdFeO 3 can be adjusted by sintering temperature. • GdFeO 3 can be applied in new field of metamaterials for antennas. [ABSTRACT FROM AUTHOR]

The high strength of most Mg-RE alloys is frequently accomplished by high RE addition, but their high density and poor plasticity restrict their applications in the field of aerospace. Focused on this problem, a novel process of the thermomechanical treatment based on multi-directional forging is developed to improve the strength and ductility of low RE content Mg-6.5Gd-1.2Y-0.49Zr (wt%) alloy simultaneously. The mechanisms of high strength and good ductility are revealed by analyzing the deformation behavior, the dynamic recrystallization (DRX) behavior, the work hardening behavior and the strengthening mechanism. The bimodal grain structure, along with the fine grain size of ∼0.8 µm and the coarse grain size of ∼11.6 µm, is prepared after a 4-pass-MDF process, which is ascribed to DRX during MDF and recovery during the interpass annealing. After a peak aging treatment, the ultimate tensile strength reaches 378.4 MPa, the yield strength 324.3 MPa and the elongation to failure 19.0%, respectively. The enhanced strength is more related to the combined effect of aging precipitation of β′ phase and grain refinement, while the good ductility benefits from the ability of bimodal structure to coordinate deformation, the excellent work-hardening effect and the full activation of slip. • An excellent combination of strength and ductility was achieved through a novel thermomechanical process based on MDF. • The high ductility mechanism was revealed based on the deformation, the work hardening and the DRX behaviors. • The respective contributions of different strengthening mechanisms were quantitatively analyzed. [ABSTRACT FROM AUTHOR]

Abstract The effect of FeSi powder with volume fraction of 0–40% on the soft magnetic properties of the FeSiBPNb amorphous powder cores has been systematically investigated in this study. The results shows that the amorphous magnetic powder core mixed with 10% FeSi powders in volume fraction exhibits superior DC-bias properties, constant permeability, low core loss up to a higher frequency range, and excellent soft magnetic properties after appropriate heating treatment. The DC-bias properties of the present amorphous magnetic cores decrease by only 20% as the external field increases to 100 Oe. Meanwhile, it also exhibits a high permeability of 60 at 10 MHz and a low core loss of 159 W/kg at B m = 0.1 T and f = 50 kHz. The present Fe-based amorphous magnetic powder cores mixed FeSi powders with superior DC-bias properties are a potential candidate for a variety of industrial applications. Highlights • Amorphous FeSiBPNb/FeSi compound powder cores were successfully prepared. • The powder cores mixed with 10% FeSi powders show the best magnetic properties. • The compound powder cores exhibit superior DC-bias properties and low core loss. [ABSTRACT FROM AUTHOR]

Bi 4 LaFeTi 3 O 15 films were deposited on (111)Pt/Ti/SiO 2 /Si using a sol-gel process. The films have a four-layered Aurivillius structure with random orientation, which were confirmed by x-ray reflectivity and grazing incidence x-ray diffraction. As expected, the films show room-temperature multiferroic properties with a remanent polarization P r of ∼17 μC/cm 2 and a saturated magnetization M s of ∼1.4 emu/cm 3 . More interestingly, a strong magneto-electric coupling was observed at room temperature with a converse magnetoelectric coefficient of 21% and a magneto-dielectric coefficient of 2%, resulting from the local Fe 2+ /Fe 3+ charge ordering. Both x-ray photoelectron spectroscopy and temperature-dependent dielectric spectra provide evidence that the Fe 2+ and Fe 3+ coexist in Bi 4 LaFeTi 3 O 15 films. [ABSTRACT FROM AUTHOR]

Mg 1-x Cd x Co 0.05 Fe 1.95 O 4 ferrites are proposed for high frequency radar antennas, where x varies with the value of 0.0, 0.2, 0.3 and 0.4. With 5 wt% Bi 2 O 3 added for low temperature co-fired ceramic (LTCC) application, the spinel ferrites synthesized at 930 °C reveal fairly excellent magnetic and dielectric properties. X-ray diffraction indicates the processed samples present normal spinel peaks and Bi 24 Fe 2 O 39 (BFO) peaks. The existing BFO tailors the real part of magnetic permeability ( ε ′) and dielectric permittivity ( μ ′) to be approximately equal (x = 0.4, ε '≈ μ '≈26) at a wide frequency range from 1 MHz to 100 MHz. Meanwhile, the LTCC-processed samples have ultra low dielectric loss tanδ ε and magnetic loss tan δ μ (tan δ ε ≈0.0008, tan δ μ ≈0.03, x = 0.3). In addition, the high saturation magnetization and appropriate coercivity mean enhanced magnetization. These eminent magneto-dielectric characteristics enable the materials to possess a farther study-worthy necessarity. [ABSTRACT FROM AUTHOR]

A novel amorphous soft magnetic composites (ASMCs) for hundreds MHz frequency applications have been prepared under the hot-pressing molding by ultrafine submicron FeBP amorphous powders. These ultrafine submicron FeBP amorphous particles were synthesized with the NaBH 4 chemical reduction method and the particles size was regulated by the drop rate of the reducing agent. The morphology, microstructure, elemental composition and high-frequency magnetic properties of the amorphous soft magnetic composites was systematically investigated. The particle sizes of FeBP amorphous powders are distributed in 600–900 nm which gradually increase with the decrease of the drop rate of the NaBH 4 aqueous solution. Meanwhile, the Fe element content and saturation magnetization strength of the amorphous powder increase and the coercivity gradually decreases. The corresponded ASMCs also appear a commensurate permeability in the range of 6–9 responding to the GHz high frequency range with the lowest loss tangent only 0.20 and 0.44 at 500 MHZ and 1 GHz, respectively. Such ultrafine amorphous soft magnetic composites have enormous potential for high frequency applications in wide band gap semiconductor switching power supplies, RF inductors and chips. • The spherical amorphous powder was prepared by chemical reduction method with outstanding magnetic properties. • The particle size of the amorphous powder was regulated by adjusting the drop rate of the reducing agent solution. • The relationship between the powder particle size and the magnetic and electrical properties of ASMCs was elucidated. [ABSTRACT FROM AUTHOR]

For seeking a lightweight thermochromic film acting as a smart radiation device in thermal control system for spacecraft, the (La,Ca,K)MnO 3± δ films with different thicknesses were deposited on Si(100) substrate by magnetron sputtering method with a target which was synthesized by a sol-gel method. The crystal structure and micro-morphology of these films are investigated. The results reveal that all films form an orthorhombic perovskite structure, and it undergoes a Volmer-Weber growth mode with the increased thickness. Temperature-dependent infrared reflectivity and emittance are investigated. Spectra data indicate that reflectivity of all films has a decreased trend with increasing temperature. In the temperature range of 173–373 K, the K-doped thermochromic films show a large emittance increment near 0.36 with film thickness only 321 nm. All of these results show that the thermochromic film has a great potential to be applied to a more lightweight and cost-effective thermal control device in spacecraft with an excellent radiation performance. [ABSTRACT FROM AUTHOR]

A cobalt-free perovskite oxide Bi 0.5 Sr 0.5 Fe 0.8 Cu 0.2 O 3− δ (BSFC) has been investigated as novel cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The BSFC cathode exhibits good thermal stability and chemical compatibility with Ce 0.9 Gd 0.1 O 1.95 (CGO) electrolyte below 950 °C. The average thermal expansion coefficient (TEC) of BSFC is 13.1 × 10 −6 K −1 within a temperature range of 50–800 °C in air, which is close to that of CGO electrolyte. Meanwhile, the polarization resistant values ( R P ) of BSFC cathode on CGO electrolyte are 0.13, 0.32 and 0.76 Ω cm 2 at 700, 650 and 600 °C, respectively; the lowest cathode overpotential is 37 mV at a current density of 125 mA cm −2 at 700 °C in air. The CGO electrolyte-supported single cell with BSFC cathode exhibits maximum power density of 290 mW cm −2 at 700 °C using dry H 2 as the fuel. The rate-limiting step for oxygen reduction reaction (ORR) on BSFC cathode is oxygen surface adsorption-dissociation process. The attractive electrochemical performance demonstrates that BSFC oxide is a promising cathode material for IT-SOFCs. [ABSTRACT FROM AUTHOR]

Pr 2 CuO 4 - x Ce 0.9 Gd 0.1 O 1.95 (PCO- x CGO, x = 0, 10, 20, 30, 40, 50 wt%) composite cathodes were investigated for potential application in intermediate-temperature solid oxide fuel cells (IT-SOFCs). The effect of different sintering temperature on the microstructure and electrochemical performance of the composite cathode was observed. The oxygen reduction reaction (ORR) mechanism was analyzed by the electrochemical impedance spectroscopy. It was found that the addition of CGO in PCO cathode significantly reduced the polarization resistance ( R p ). The lowest R p of 0.12 Ω cm 2 for PCO-40CGO composite cathode at 700 °C in air. Oxygen partial pressure dependence study indicates that the charge transfer process is rate-limiting step for ORR on the electrode. The maximum exchange current density i 0 of the PCO-40CGO composite cathode was 15.10 mA cm 2 at 700 °C. All above properties indicate that the PCO-40CGO composite is a promising cathode material for IT-SOFCs. [ABSTRACT FROM AUTHOR]

Fe‐0.5C‐11Cr corrosion resistant alloy coating was prepared on the surface of 3Cr13 stainless steel by powder feeding laser cladding, and the microstructure of the coating layer was controlled by solution aging treatment. The microstructure of the coatings was measured by scanning electron microscopy, and phase composition was determined by X-ray diffraction. The hardness and corrosion resistance of coatings before and after heat treatment were evaluated on microhardness tester and electrochemical workstation, respectively. The results show that the morphology, size and quantity of dendrite carbides in the cladding layer of Fe‐0.5C‐11Cr alloy can be improved by solution and aging treatment. The eutectic carbides in the cladding layer can be changed from block, bone, continuous network of grain boundaries to round granular and discontinuous short rod by solution and aging treatment, which greatly improves the uniformity of the microstructure. There is a dynamic equilibrium and critical time for the melting and growth of carbides at 1050 °C. When the holding time is less than 20 min, the size of carbide decreases with time. After 20 min, fine carbides agglomerate and grow with time. The hardness of the cladding layer after heat treatment is about 9% higher than that of the cladding layer without heat treatment and the uniformity of the hardness is improved. The corrosion resistance of the sample kept for 20 min at 1050 ℃ is the superior because the pitting potential and passivation zone width of the coating kept at 1050 ℃ for 20 min increased by 21.5% and 19.2% compared with the cladding laser without heating, respectively. • Fe-0.5C-11Cr high-hardness corrosion-resistant alloy coating was prepared on the surface of 3Cr13 stainless steel by powder feeding laser cladding, and the hardness and corrosion resistance of the cladding layer were significantly improved by heat treatment. • The effects of carbide microstructure, phase composition and Cr content on corrosion resistance were investigated. • The distribution, morphology and size of grain boundary carbide were improved by solution and aging treatment. • The quantitative correspondence among corrosion resistance, hardness, composition and size of carbide phase was established to achieve a good combination of mechanical properties and corrosion resistance of cladding layer. [ABSTRACT FROM AUTHOR]

Cobalt-based spinel oxides are a promising class of electro-catalysts for oxygen evolution reaction (OER). Herein, a series of Mg(Co 1−x Fe x) 2 O 4 (x = 0.0–1.0) oxides are designed as OER catalysts. MgCo 2 O 4 is selected to fix Co3+ in the octahedral position, which is active site for the OER. We elucidate the volcanic relationship between the OER activity and Fe substitution concentration in Mg(Co 1−x Fe x) 2 O 4 , which shows an optimal activity at 20 at% Fe substitution. Superconducting Quantum Design (SQUID) technique reveals that Fe substitution tunes the e g orbital electronic configuration of Co3+ from low spin to high spin. The optimized e g occupancy of 0.91 is obtained in MgCo 1.6 Fe 0.4 O 4. Density functional theory calculations verify that the improved OER performance stems from the enhanced Co-O covalence after Fe substitution, which promotes the transfer of electrons from oxygen, thus accelerates the catalytic oxygen evolution reaction. The formation energy of O* decrease as well by Fe substitution, and the conversion of OH* into O* is identified to be the rate-determining step. This work complements the optimizing electronic configuration of cobalt cations for OER and provides favorable principles for the rational design of OER electro-catalysts. [Display omitted] • Fe doped MgCo 2 O 4 oxides are evaluated as OER catalysts for the first time. • Fe substitution optimizes the e g orbital electronic configuration of Co3+ ions. • Fe substitution enhances Co-O covalency, and facilitates the injection/ extraction of electrons from oxygen to cobalt. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fe80 − x Ni x P14B6 (x =20–50at.%) BMGs were prepared by fluxing and J-quenching techniques. [•] The highest GFA is reached at x =40 and the corresponding critical diameter is up to 2.5mm. [•] The present FeNi-based BMGs exhibit very large εp and the εp of Fe30Ni50P14B6 BMG is 11.7%. [•] The present FeNi-based BMGs have much higher corrosion resistance than stainless steel. [Copyright &y& Elsevier]

Highlights: [•] Fe80−xNi x P13C7 (x =0–30at.%) BMGs were prepared by fluxing and J-quenching techniques. [•] The small amount of substitution of Ni for Fe can enhance the glass forming ability. [•] The substitution of Ni for Fe can greatly enhance the plastic strain of FeNiPC BMGs. [•] Fe60Ni20P13C7 BMG has a εP of >10% which is the largest one reported for Fe-based BMGs. [Copyright &y& Elsevier]

The precipitation behavior and mechanical property evolution of a superalloy, Haynes 230, were investigated during short-term aging at 800 ℃. The results demonstrated that M 6 C and four different forms of M 23 C 6 precipitated throughout aging, and the evolution of M 23 C 6 followed a sequence of intergranular precipitates, intragranular nano-precipitates, incoherent twin boundary (TB) precipitates, and peritectic precipitates enveloping the outer layer of M 6 C, all of which exhibited a semi-coherent cubic-to-cubic relationship with the austenitic matrix. Among them, the intergranular M 23 C 6 was mainly lamellar. The lamellar M 23 C 6 formed through a discontinuous reaction, resulting from the decomposition of the supersaturated matrix and alternating with the γ matrix. Intragranular nano-M 23 C 6 precipitated preferentially at dislocations, while incoherent TB M 23 C 6 grew along the {111} direction of the twin plane. In addition, peritectic M 23 C 6 was a product of the degradation reaction of M 6 C at 800 ℃, with higher W and Cr than the other forms of M 23 C 6. Overall, the significant changes in microstructure and properties of alloy 230 during aging at 800 ℃ were concentrated in the first 200 h. At this stage, the precipitation amount of carbides increased dramatically, which enhanced the strength and hardness to peaks by hindering the dislocation motion. Meanwhile, ductility and toughness decreased significantly on account of the reduction of grain boundary bonding strength caused by lamellar M 23 C 6. With the extension of aging time, the tensile fracture mode at room temperature shifted from transgranular to intergranular fracture, and intergranular M 23 C 6 gradually became the preferential crack source. • The nucleation and growth mechanism of precipitates in alloy 230 were revealed. • Four different types of M 23 C 6 carbides were found for the first time in alloy 230. • Peritectic M 23 C 6 has higher W and Cr than other forms of M 23 C 6. • The intergranular lamellar M 23 C 6 is the product of discontinuous reaction. • It is verified that the change of alloy 230 at 800 ℃ is concentrated in the early aging period. [ABSTRACT FROM AUTHOR]

Abstract: Bulk magnetic Fe80− x Mo x P13C7 (x =0, 3, 6, 9 and 12at.%) glassy alloys were successfully prepared by the fluxing technique and J-quenching technique. The effect of Mo substitution for Fe on the glass formation ability (GFA), thermal stability, mechanical properties and magnetic properties has been studied systematically. It was found that the substitution of a small amount of Mo for Fe can dramatically enhance the GFA, which in turn, the critical maximum diameter for fully glass formation reached to 5.5mm for x =3 and 6.0mm for x =6, respectively. However, excessive substitution will promote the formation of Fe2Mo3 competition crystalline phase leading to the degradation of the GFA. Furthermore, the substitution of proper content of Mo for Fe can obviously enhance the mechanical properties of the present Fe-based alloys, which can be identified that the current FeMoPC bulk metallic glass possesses a high fracture strength (over 3000MPa) as well as a large room temperature plasticity (above 5%). In addition, the Mo doping FePC bulk metallic glasses exhibit good soft magnetic properties with a relatively high saturation magnetization of over 1.0T at room temperature. [Copyright &y& Elsevier]

Abstract: Pb[(Mg1/3Nb2/3)1− x Zr x ]O3 (x =0.03, 0.06, 0.09, 0.12) ceramics were prepared using a solid state reaction process. The phase structure and surface micrograph were analyzed by X-ray diffraction and scanning electron microscopy. The effects of Zr content on the dielectric and dielectric tunability properties were investigated systematically. The results showed that the high dielectric tunability (>75% at x =0.12), low dielectric loss (<0.15%) and high temperature stability of these relaxor ferroelectric ceramics were favorable and competitive to those of titanium-containing perovskite structure materials for tunable device applications. The high dielectric non-linear properties were further discussed in terms of the Landau–Ginsberg–Devonshire thermodynamic theory completed with a Langevin term. [Copyright &y& Elsevier]

Abstract: Differential scanning calorimetry was used to investigate the thermal behavior and non-isothermal crystallization kinetics of Fe80P13C7 glassy alloy in the forms of both bulk rod and the melt-spun ribbon. The apparent activation energy E of the first crystallization event for the ribbon and bulk samples are determined to be 432±17kJ/mol and 529±26kJ/mol, respectively, by Kissinger method, and 421±17kJ/mol and 514±26kJ/mol, respectively, by Ozawa method. It is proposed that larger the apparent activation energy E in the bulk sample may be ascribed to less amount of free volume in the supercooled liquid state of the bulk sample. The crystallization kinetics of the first crystallization event in the bulk and ribbon samples has been studied by non-isothermal approach and the local Avrami exponent for the first crystallization peak is evolved to reveal the crystallization mechanism. The local Avrami exponent of the bulk sample is less than 1.5 in the whole process for the first crystallization event, which means the crystallization mechanism of diffusion-controlled growth of pre-existing nuclei. While the local Avrami exponent for the ribbon sample is in the range of 1.5–2.5 in most cases, which means the crystallization mechanism is diffusion-controlled growth of the initial crystal type, at the same time, along with the nucleation rate decreases with time. The difference in the local Avrami exponent for the first crystallization event between the bulk and ribbon sample indicates that there are higher degree of short-range order in the bulk sample than that in the ribbon sample in the supercooled liquid state. These results distinctly indicate that the difference of crystallization behavior for the first crystallization event between the bulk and ribbon samples of Fe80P13C7 glassy alloy results from the difference nature in their supercooled liquid states which is related to the as-prepared state of samples. [Copyright &y& Elsevier]

Exploring high-performance and durable cathode materials can accelerate the commercialization of intermediate/low-temperature solid oxide fuel cells (SOFCs). Herein a highly active and CO 2 -tolerant perovskite cathode, Pr 0.94 Ba 0.7 Ca 0.3 Co 2 O 5+ δ (P 0.94 B 0.7 Ca 0.3 C), is well-designed and developed for SOFCs operating below 700 °C. It is discovered that cation-ordered/disordered perovskite phases co-exist in P 0.94 B 0.7 Ca 0.3 C, induced by calcium doping. As a result, the P 0.94 B 0.7 Ca 0.3 C cathode exhibits a polarization resistance as low as 0.022 Ω cm2 at 700 °C in air. When tested under realistic conditions, an anode-supported single cell delivers a peak power density of 1202 mW cm−2 at 700 °C, along with excellent long-term stability for 120 h. Furthermore, the CO 2 tolerance of P 0.94 B 0.7 Ca 0.3 C is investigated in CO 2 -containing atmosphere, demonstrating an initial polarization resistance of 0.035 Ω cm2 in air with 10 vol% CO 2 at 700 °C, which increases to 0.053 Ω cm2 after a 13 h operation. The degradation rate is merely ∼1/4 of that for the state-of-the-art Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3- δ (BSCF) cathode. The outstanding ORR kinetics and durability highlight the potential of P 0.94 B 0.7 Ca 0.3 C as a promising cathode candidate for SOFCs operating below 700 °C. • A series of Pr 0.94 Ba 1- x Ca x Co 2 O 5+ δ perovskites are studied systematically. • P 0.94 B 0.7 Ca 0.3 C cathode gives a polarization resistance of 0.022 Ω cm2 at 700 °C. • P 0.94 B 0.7 Ca 0.3 C cathode-based fuel cell shows a PPD of 1202 mW cm−2 at 700 °C. • –P 0.94 B 0.7 Ca 0.3 C cathode shows a promoted CO 2 tolerance in air with 10 vol% CO 2. [ABSTRACT FROM AUTHOR]

In this experiment, the nano-ZrO 2 particles reinforced molybdenum alloy with excellent mechanical properties were prepared through liquid-liquid doping process, and the comparison with TZM alloy prepared by solid-solid doping process was conducted. During the liquid-liquid doping process, the ZrO 2 particles ensured the dispersion of the second phase in alloy because they reached molecular-level uniformity, and the hydrothermal synthesis preparation process enabled the ZrO 2 particles in alloy to reach nanometer size level. In Mo-ZrO 2 alloy, the small and dispersed ZrO 2 can effectively block dislocation and passivation cracks; both the room temperature and high temperature performance of Mo-1.5 %ZrO 2 alloy was better than that of TZM alloy. Based on the hindered recrystallization process, improved recrystallization temperature, as well as enhanced recrystallization strength thanks to the alloy pinning effect of ZrO 2 , the maximum tensile stress of Mo-1.5 %ZrO 2 alloy at 1000 ℃ was about 14 % higher than pure molybdenum, and the maximum tensile stress of Mo-1.5 %ZrO 2 alloy at 1400 ℃ was at least 45 % higher than pure molybdenum. Quantitative analysis shows that the strengthening effect of the second phase was the best during the recrystallization process. [Display omitted] • In the experiment, the liquid-liquid doping process is applied to prepare nano-ZrO 2 particle-reinforced molybdenum alloy with excellent mechanical properties. • By means of liquid-liquid doped ZrO 2 particles, the molecular-level uniformity is realized, and the dispersion of the second phase in alloy is ensured. • The pinning effect of refined and dispersed ZrO 2 can effectively hinder the recrystallization process and improve the alloy recrystallization temperature as well as strength. [ABSTRACT FROM AUTHOR]

A cost-effective and sustainable approach has been developed to synthesize N-doped carbon material from fishbone waste via a one-step carbonization without an addition of chemical activator as a catalyst. The carbonization temperature can be optimized so that a favorable layered structure is achieved in 3D-flake nitrogen-doped hierarchical porous carbon (NPC). NPC-850 (NPC that was carbonized at 850 °C) not only has a high specific surface area of up to 1337 m2 g−1, but is also richly doped with heteroatoms (N and O content of 5.8 and 7.99 at.%, respectively). NPC-850 also exhibits an excellent electrochemical supercapacitor (SC) performance, i.e., a maximum specific capacitance of 476 F g−1 in a three-electrode system and 354 F g−1 in a symmetrical SC (both in a 1 M H 2 SO 4), and a maximum energy density of 21.2 Wh kg−1 in a symmetrical SC (in a 1 M TEABF 4 /AN). Moreover, NPC-850 can achieve high cycling stability, with 90.9% retaining of the original capacitance after 10,000 continuous cycles at a 1 A g−1 current density. Such an outstanding performance suggests that our facile and scalable synthesis technique is effective to prepare porous carbon from biomass for electrochemical energy storage. Image 1 • Fishbone was carbonized to produce N-doped carbon without chemical activation. • NPC-850 has a high specific surface area of up to 1337 m2 g−1. • As supercapacitor electrode, NPC-850 can achieve specific capacitance of 476 F g−1. • NPC-850 retains ∼91% of original capacitance after 10,000 continuous cycles. [ABSTRACT FROM AUTHOR]

Abstract Oxygen and impurities are basically unavoidable during the manufacturing of Fe-based metallic glasses, frequently impeding the products' performance and greatly increasing the processing cost. Until now, how oxygen affects the glass-forming ability remains controversial, and eliminating the adverse effects of oxygen and impurities is still a huge challenge. Here we discover a new force of oxide inclusion flotation that drives the occurrence of purification, by blowing oxygen into the Fe-based melts, which help to mix the melts well to accelerate the oxidization and elimination of impurities from commercial raw materials. The synergistic reaction of oxygen and impurities not only improves the glass forming ability, magnetic and mechanical properties of the products, but also makes the stringent processing requirements, e.g. high-purity starting materials and/or high-purity argon, unnecessary. This study uncovers the mystery of oxygen in the glass formation, extends the innovation of fabrication process and highlights a significant technological breakthrough to reduce industrial production cost of Fe-based metallic glasses. Highlights • A new force of oxide inclusion flotation in Fe-based melts was discovered. • The mystery of oxygen in the glass formation for Fe-based BMGs was revealed. • Mechanism of purification by oxygen in Fe-based melts was proposed. [ABSTRACT FROM AUTHOR]