首页期刊导航|Journal of Alloys and Compounds
期刊信息/Journal information
Journal of Alloys and Compounds
Elsevier Science S.A.
Journal of Alloys and Compounds

Elsevier Science S.A.

0925-8388

Journal of Alloys and Compounds/Journal Journal of Alloys and CompoundsSCIISTPEI
正式出版
收录年代

    (165433)Lattice disorder effect on the structural, ferroelectric and electrocaloric properties of (Ba, Sr, Ca)TiO_3 ceramics

    Jie WuGaochao ZhaoChengbing Pan
    7页
    查看更多>>摘要：We report the effect of A-site disorder σ~2 on the structural, dielectric, ferroelectric (FE) and electrocaloric (EC) properties of lead-free Ba_(1-x-y)Sr_xCa_yTiO_3 (0.025 ≤ x ≤ 0.3, 0.275 ≤ y ≤ 0.113) perovskites. We have synthesized a series of samples with the same A-site cationic mean radius but different A-site ionic radii variance (i.e., A-site disorder) σ~2. The tetragonal distortion and FE Curie temperature TC are found to decrease with decreasing A-site disorder σ~2. The temperature of the maximum EC effect decreases from ~120-27 °C with decreasing disorder σ~2. The highest adiabatic temperature change ΔT obtained using both the direct and indirect methods reaches ~0.8 K for the sample with optimized A-site disorder σ~2. Our results suggest that, in addition to the lattice distortion, the lattice disorder might be a new and effective parameter for promoting the EC effect.
      原文链接:
    • NSTL
    • Elsevier

    (165396)Understanding the formation of a cubic Mn_(0.6)Fe_(0.4)S solid-solution anode and its high performance for rechargeable lithium-ion batteries

    Deli LiLingling ZhangJun Liang
    10页
    查看更多>>摘要：A cubic Mn_(0.6)Fe_(0.4)S solid solution material has been synthesized using a scalable in situ sulfuration treatment of Prussian-blue analogs (PBAs), and its phase formation process and Li-storage mechanism were investigated. Increased treatment temperature and time encourage a phase transformation from hexagonal Fe_7S_8 to cubic FeS_2 during the sulfuration process, which results in the formation of a solid solution between cubic FeS_2 and cubic MnS. The resulting Mn_(0.6)Fe_(0.4)S solid solution electrode exhibits high initial coulombic efciency, excellent rate performance, and superior cycling stability (520 mA h g~(-1) after 1000 cycles at 1.0 A g~(-1)). Ex-situ X-ray diffractometry and electro-kinetics tests show that the doping-induced structural phase transition in Mn_(0.6)Fe_(0.4)S solid solution creates a favorable electronic structure and ensures rapid charge transfer kinetics during the lithiation/delithiation process, simultaneously achieving high energy conversion efciency and a long lifespan.
      原文链接:
    • NSTL
    • Elsevier

    (165428)Self-powered photosensor based on curcumin:reduced graphene oxide (CU:rGO)/n-Si heterojunction in visible and UV regions

    Hulya Ozturk DoganZeynep OrhanFatma Y?ld?r?m
    11页
    查看更多>>摘要：This study proposes a novel photosensor that uses curcumin:reduced graphene oxide/silicon (CU:rGO)/n-Si heterojunction, prepared at different molar ratios of rGO with CU. The CU:rGO was deposited on an n-Si by electrochemically. The EDX, XRD, SEM and absorbance analyses of CU:rGO flm were investigated. From the I-V measurements, the all CU:rGO/n-Si devices showed excellent rectifcation characteristics both in the dark and under various illumination intensities. The device with higher rGO ratio (labelled D1) had better performance overall having the rectifcation ratio of 86094, the ideality factor of 2.15 and photosensitivity of 198 (at 150 mW/cm~2), which was attributed to the extraordinary electro-optical properties of rGO. Hence, the electrical and optical properties of D1 device were analyzed in detailed. The typical I-V measurements were conducted both in dark and under AM 1.5 G illumination of various light intensities. The intensity of the incident light varied from 10 to 150 mW/cm~2. The photocurrent exhibited a strong dependence on the light intensity. The I-V measurements of another device (labelled D4) prepared under the same conditions were achieved at 365 nm and 395 nm wavelengths and it showed good sensitivity to light even in the UV region. Furthermore, both D1 and D4 devices operated in self-powered mode in visible and UV light without the need for any external voltage. According to the experimental results, the produced CU:rGO/n-Si devices can be potential devices for photosensor applications in a wide spectral region.
      原文链接:
    • NSTL
    • Elsevier

    (165417)Oxidation states and occupation sites of Fe and Cu ions in the Y_3Fe_(5-x)Cu_xO_(12), (0.00 ≤ x ≤ 0.05) compound synthesized via sol gel method

    L. LealJ. Matilla-AriasY. Guerra
    12页
    查看更多>>摘要：This paper presents an experimental and theoretical study on the oxidation states and occupation sites of Fe and Cu ions in the Y_3Fe_(5-x)Cu_xO_(12), (0.00 ≤ x ≤ 0.05) compound synthesized via sol gel method. Transmission electron microscopy images showed agglomerated coral-shaped particles, while selected area electron diffraction analysis confrmed the formation of YIG cubic structure, since the bright points correspond to the (004), (123), (024), (224), (022), and (112) YIG family planes. Fourier transform infrared and Raman spectroscopies testifed the YIG crystal structure formation and suggest that the Fe by Cu replacement occurs in the octahedral sites. The cation distribution and reticular energy were estimated theoretically, revealing that the more probable valence state combination corresponds to Cu~+-Fe~(2+) doped YIG confg-uration. The experimental study by X-ray Photoelectron Spectroscopy certifed the elements valence states and confrmed that Y, Fe and Cu are mainly in the Y~(3+), Fe~(3+), Fe~(2+) and Cu~+ oxidation states. The oxygen vacancies formation was also identifed through the deconvolution of XPS spectra for the oxygen region. Finally, the dopant occupation probability per site as function of dopant concentration per unit formula was calculated using a phenomenological model and suggested that Cu+ and Fe~(2+) cations prefer to occupy the octahedral sites in the YIG crystal structure.
      原文链接:
    • NSTL
    • Elsevier

    Corrosion behavior of Mg-5.7Gd-1.9Ag Mg alloy sheet

    Xu, BingqianWu, GuosongLi, BangjunSun, Jiapeng...
    10页
    查看更多>>摘要：This paper focuses on the corrosion behavior of Mg-5.7Gd-1.9Ag alloy sheets with high strength-ductility synergy in the 3.5 wt% NaCl solution prepared by a combined route of rolling and aging. Electrochemical measurements indicate that the rolled sheet exhibits a significantly improved corrosion resistance as compared to its as-cast counterpart. Subsequent aging, as a widely used strengthening method, decreases corrosion resistance to a certain extent. However, the aged sheet still has enhanced corrosion resistance as compared to its as-cast counterpart. The observed corrosion migration in the present Mg-5.7Gd-1.9Ag Mg alloy mainly stems from the evolution of second phases, but not the grain size and texture. A small number of the micron beta phase particles is incapable of promoting severe galvanic corrosion and thus endows the rolled sheet with good corrosion resistance, while the massive submicron beta phase particles along grain boundaries and dense gamma '' nanoplates within grains in the aged sheet bring out severe galvanic corrosion and thus accelerate corrosion. (c) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Honeycomb-like SnS2/graphene oxide composites for enhanced microwave absorption

    Man, QikuiTan, GuoguoGao, YuPan, Lining...
    9页
    查看更多>>摘要：Achieving the broad effective absorption bandwidth (EAB), strong absorption capacity and thin matching thickness are still a huge challenge for the dielectric loss-type microwave absorbers. Here, the honeycomblike SnS2/ graphene oxide (GO) composites are fabricated via a facile chemical bath deposition method to optimize the microwave absorption performances. The 2D SnS2 nanosheets are uniformly and vertically grown on the GO sheets, forming a highly open hierarchical network, which can be beneficial to enhance the multiple scatterings and reflections of incident electromagnetic wave. Meanwhile, the impedance matching (Z) and attenuation constant (alpha) of composites are well-tuned by changing the SnS2 content in the composites. When the GO sheets are just completely coated by SnS2 nanosheets, the SnS2/GO composite exhibits excellent microwave absorption ability with the minimum reflection loss (RLmin) of - 59.2 dB and EAB of 5.4 GHz (12.3-17.7 GHz) at the thickness of only 1.45 mm, which is mainly ascribed to the strong interfacial polarization and good impedance matching. This work provides a significant guidance to achieve excellent absorption performance with broad EAB and strong absorption for dielectric loss-type absorbers. (c) 2022 Published by Elsevier B.V.
      原文链接:
    • NSTL
    • Elsevier

    Plasmonic Au activates anchored Pt-Si bond in Au-Pt-SiC promoting photocatalytic hydrogen production

    Wang, DaLi, ZiyanZhang, HuilingSun, Jingwen...
    8页
    查看更多>>摘要：The localized surface plasmon resonance effect (LSPR) with kinetic energies and interfacial transfer dynamics can highly improve the separation of photo-generated carriers. We demonstrate here that a plasmonic catalyst Au-Pt-SiC has been prepared by a facile reduction-photo-deposition technique. The Pt-Si bond is formed on the SiC surface to construct an excellent channel for accelerating photo-electrons transfer from SiC to Pt. The LSPR of Au with electrons-deficiency property further activates the anchored Pt-Si bond, and motivates an oriented high-efficient photo-electrons transport channel among the Au, Pt and SiC. This channel accelerates the excited electrons in SiC to transfer to cocatalysts and thus improves the photo-generated charge carriers separation. The LSPR of Au also harvests light energy efficiently to broaden the light absorption range. Consequently, the rate of photocatalytic water reduction for H-2 is enhanced to 2248.5 mu L h(-1) g(-1) in Au-Pt-SiC, 2.1 times higher than that of the individual Pt loading. (C) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier

    Exploiting different morphologies of non-ferromagnetic interacting precursor?s for preparation of hexaferrite magnets

    Vijayan, HarikrishnanPovlsen, AmalieThomas-Hunt, JackMorch, Mathias Ibsen...
    9页
    查看更多>>摘要：Sintered cold compacted hexaferrite magnets with appreciable magnetic properties and crystallite alignment were made from non-magnetic precursors without applying an external magnetic field. This work presents a novel approach employing non-ferromagnetic interacting precursors comprising of platelet shaped six-line ferrihydrite and needle shaped goethite nanoparticles. A hydrothermal synthesis route was employed to produce platelet shaped six-line ferrihydrite of ~5 nm thickness. Needle shaped goethite nanoparticles were likewise prepared by hydrothermal synthesis with apparent dimensions of ~10 x 27 x 10 nm3 extracted from X-ray powder diffraction data. The powder diffraction Rietveld modelling also revealed the presence of an amorphous phase in the six-line ferrihydrite and a SrCO3 impurity. The presence of needle shaped goethite nanoparticles improves the alignment of magnets, while retaining the coercivity (Hc), in contrast to hexaferrite magnets prepared from six-line ferrihydrite by spark plasma sintering (SPS). The non-ferromagnetically interacting precursors were directly converted to the SrFe12O19 magnets by pressing them with conventional compaction technique followed by subsequent sintering of the pellets. Decoupling the pressing and sintering step is interesting for industrial production of magnets. The hexaferrite magnets prepared displayed good combination of saturation magnetization Ms = 70 Am2/kg and coercivity Hc = 297 kA/m with some degree of alignment of the crystallites Mr/Ms = 0.71. This procedure exploits the anisotropic shape of the crystallites and compaction using uniaxial pressure followed by sintering into aligned bulk magnets. Two sets of hexaferrite bulk magnets were prepared by sintering at 900 degrees C and held for 2 h and 1050 degrees C with a holding time 0 min. The hexaferrite magnets sintered at 1050 degrees C were subjected to transmission pole figure analysis. The texture index for each pellet were extracted from the pole figure analysis. Employing needle shaped goethite nanoparticles actually enhanced the alignment of the hexaferrite magnets. The magnet obtained from only six-line ferrihydrite displayed only a slightly improved texture index when compared with mixture of six-line ferrihydrite and goethite nanoparticles. (c) 2022 The Author(s). Published by Elsevier B.V. CC_BY_4.0
      原文链接:
    • NSTL
    • Elsevier

    Highly soluble Ni-salen molecules enable boosted photocatalytic hydrogen evolution of polymeric carbon nitride/CdS heterojunction

    Zhu, ChuhongYu, ZhiwuYuan, YupengLin, Xiangang...
    8页
    查看更多>>摘要：The photocatalytic hydrogen (H2) evolution of photocatalyst generally requires the assistance of cocatalysts, which are mainly centered on noble metals, such as Pt and Au. However, noble metals cocatalysts often suffer from the uneven distribution and severe aggregation, as well as scarcity. Herein, we reported nickelsalen (Ni-salen) molecules on the promotion of photocatalytic H2 evolution with polymeric carbon nitride (PCN)/CdS heterojunction, in which the noble metal free Ni-salen molecules are soluble and highly dispersed during photocatalytic H2 evolution under visible light irradiation (lambda >= 420 nm). Under optimized loading concentration of the Ni-salen molecules (0.03 mM), the highest H2 evolution rate is up to 23.3 mmol g-1 h-1, which is more than 4 times higher than that by using PCN/CdS heterojunction alone. In addition, Ni-salen molecules are highly stable and can offer a durable H2 evolution with 28 h. The enhancement on H2 evolution is the result of efficient photogenerated electrons transfer from photoexcited PCN/CdS heterojunction to the coordination unsaturated Ni active centers of Ni-salen molecules. This work demonstrates the great potential of soluble noble metal free Ni-salen molecules on the promotion of photocatalytic H2 evolution.
      原文链接:
    • NSTL
    • Elsevier

    Insights on phase formation from thermodynamic calculations and machine learning of 2436 experimentally measured high entropy alloys

    Wang, ChuangyeZhong, WeiZhao, Ji-Cheng
    12页
    查看更多>>摘要：Both CALPHAD (CALculation of PHAse Diagrams) and machine learning (ML) approaches were employed to analyze the phase formation in 2436 experimentally measured high entropy alloy (HEA) compositions consisting of various quinary mixtures of Al, Co, Cr, Cu, Fe, Mn, and Ni. CALPHAD was found to have good capabilities in predicting the BCC/B2 and FCC phase formation for the 1761 solid-solution-only compositions, excluding HEAs containing an amorphous phase (AM) or/and intermetallic compound (IM). Phase selection rules were examined systematically using several parameters and it was revealed that valence electron concentration (VEC) < 6.87 and VEC > 9.16 are the conditions for the formation of single-phase BCC/B2 and FCC, respectively; and CALPHAD could predict this with essentially 100% accuracy. Both CALPHAD predictions and experimental observations show that more BCC/B2 alloys are formed over FCC alloys as the atomic size difference between the elements increases. Four ML algorithms, decision tree (DT), k-nearest neighbor (KNN), support vector machine (SVM), and artificial neural network (ANN), were employed to study the phase selection rules for two different datasets, one consisting of 1761 solid-solution (SS) HEAs without AM and/or IM phases, and the other set consisting of all the 2436 HEA compositions. Cross validation (CV) was performed to optimize the ML models and the CV accuracies are found to be 90.4%, 94.1%, 93.8%, 89.7% for DT, KNN, SVM, and ANN respectively in predicting the formation of BCC/B2, BCC/B2 + FCC, and FCC; and 92.9%, 96.3%, 96.9%, 92.3% for DT, KNN, SVM, and ANN respectively in predicting SS, AM, SS + AM, and IM phases. Sixty-six experimental bulk alloys with SS structures are predicted with the trained ANN model, and the accuracy reaches 80.3%. VEC was found to be most important parameter in phase prediction for BCC/B2, BCC/B2 + FCC, and FCC phases. Electronegativity difference and FCC-BCC-index (FBI) are the two dominating features in determining the formation of SS, AM, SS + AM, and IM. A separation line delta H-mix = 29 x VEC - 247 was found in the delta H-mix-vs-VEC plot to predict the formation of single-phase BCC/B2 or FCC with a 96.2% accuracy (delta H-mix = mixing enthalpy). These insights will be very valuable for designing HEAs with targeted crystal structures. (c) 2022 Elsevier B.V. All rights reserved.
      原文链接:
    • NSTL
    • Elsevier