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Ti_(3)AlC_(2−y)N_(y) carbonitride MAX phase solid solutions with tunable mechanical,thermal,and electrical properties
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作者 Weiwei Zhang Shibo Li +3 位作者 Shukai Fan Xuejin Zhang Xiachen Fan Guoping Bei 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1473-1481,共9页
Changing the N content in the Ti_(3)AlC_(2−y)N_(y) MAX phase solid solutions allows for the fine-tuning of their properties.However,systematic studies on the synthesis and properties of Ti_(3)AlC_(2−y)N_(y) solid solu... Changing the N content in the Ti_(3)AlC_(2−y)N_(y) MAX phase solid solutions allows for the fine-tuning of their properties.However,systematic studies on the synthesis and properties of Ti_(3)AlC_(2−y)N_(y) solid solution bulks have not been reported thus far.Here,previously reported Ti_(3)AlC_(2−y)N_(y) solid solution bulks(y=0.3,0.5,0.8,and 1.0)were synthesized via hot pressing of their powder counterparts under optimized conditions.The prepared Ti_(3)AlC_(2−y)N_(y) bulks are dense and have a fine microstructure with grain sizes of 6–8μm.The influence of the N content on the mechanical properties,electrical conductivities,and coefficients of thermal expansion(CTEs)of the prepared Ti_(3)AlC_(2−y)N_(y) bulk materials was clarified.The flexural strength and Vickers hardness values increased with increasing N content,suggesting that solid solution strengthening effectively improved the mechanical properties of Ti_(3)AlC_(2−y)N_(y).Ti_(3)AlCN(y=1)had the highest Vickers hardness and flexural strength among the studied samples,reaching 5.54 GPa and 550 MPa,respectively.However,the electrical conductivity and CTEs of the Ti_(3)AlC_(2−y)N_(y) solid solutions decreased with increasing N content,from 8.93×10^(−6) to 7.69×10^(−6) K^(−1) and from 1.33×10^(6) to 0.95×10^(6) S/m,respectively.This work demonstrated the tunable properties of Ti_(3)AlC_(2−y)N_(y) solid solutions with varying N contents and widened the MAX phase family for fundamental studies and applications. 展开更多
关键词 MAX solid solutions Ti_(3)AlC_(2−y)N_(y) microstructure mechanical properties electrical conductivity thermal expansion
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Improvement effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)on hydrogen storage performance of MgH_(2)
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作者 Yingyan Zhao Zhibing Liu +5 位作者 Jiangchuan Liu Yunfeng Zhu Jiguang Zhang Yana Liu Xiaohui Hu Liquan Li 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期197-208,共12页
The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were suc... The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were successfully prepared and introduced into MgH_(2)(denoted as MgH_(2)-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH_(2)-11 wt.%NiCu@C are 175.0℃and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH_(2)-11 wt.%NiCu@C,which is lower than half of that of the as-milled MgH_(2).Moreover,MgH_(2)-11 wt.%NiCu@C displays great cyclic stability.The strengthening"hydrogen pumping"effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH_(2).This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields. 展开更多
关键词 Magnesium hydride Reversible solid solution Core-shell nanoparticles Hydrogen storage performance
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Hydrogen storage properties of magnesium hydride catalyzed by Ni-based solid solutions 被引量:5
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作者 Jian ZHANG Liu HE +3 位作者 Yuan YAO Xiao-jie ZHOU Li-kun JIANG Ping PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第2期604-617,共14页
The Ni−25%X(X=Fe,Co,Cu,molar fraction)solid solutions were prepared and then doped into MgH_(2) through high-energy ball milling.The initial dehydrogenation temperatures of MgH_(2)/Ni−25%X composites are all decreased... The Ni−25%X(X=Fe,Co,Cu,molar fraction)solid solutions were prepared and then doped into MgH_(2) through high-energy ball milling.The initial dehydrogenation temperatures of MgH_(2)/Ni−25%X composites are all decreased by about 90℃relative to the as-milled pristine MgH_(2).The Ni−25%Co solid solution exhibits the most excellent catalytic effect,and the milled MgH_(2)/Ni−25%Co composite can release 5.19 wt.%hydrogen within 10 min at 300℃,while the as-milled pristine MgH_(2) can only release 1.78 wt.%hydrogen.More importantly,the dehydrogenated MgH_(2)/Ni−25%Co composite can absorb 5.39 wt.%hydrogen at 275℃within 3 min.The superior hydrogen sorption kinetics of MgH_(2)/Ni−25%Co can be ascribed to the actual catalytic effect of in-situ formed Mg_(2)Ni(Co)compounds.First-principles calculations show that the hydrogen absorption/desorption energy barriers of Mg/MgH_(2) systems decrease significantly after doping with transition metal atoms,which interprets well the improved hydrogen sorption properties of MgH_(2) catalyzed by Ni-based solid solutions. 展开更多
关键词 MgH2 Ni-based solid solutions catalytic effect hydrogen storage properties first-principles calculations
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Effect of doping elements on catalytic performance of CeO_2-ZrO_2 solid solutions 被引量:6
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作者 李梅 柳召刚 +2 位作者 胡艳宏 王觅堂 励杭泉 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期357-361,共5页
CeZr, CeYZr, LaCeZr, LaCePrZr, LaCePrYZr, and LaCePr solid solutions were prepared via the coprecipitation method, and characterized by means of X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques.... CeZr, CeYZr, LaCeZr, LaCePrZr, LaCePrYZr, and LaCePr solid solutions were prepared via the coprecipitation method, and characterized by means of X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques. The oxygen storage capacity (OSC) of the solid solutions was evaluated by the pulse technique and the catalytic activity was assessed using a 4-channel catalysis device. It was seen that the solid solutions presented cubic structure. The specific surface area and thermal stability could be enhanced by doping Y into the solid solutions. Doping a small amount of La had a positive effect on the thermal durability while doping a large amount of La decreased the specific surface area and the thermal stability. LaCePrZr and LaCePrYZr solid solutions synthesized using Baotou rare earth mineral residue enriched with LaCePr after Nd extraction presented a certain higher value in specific surface area and thermal stability, thereby enabling to be used as economic catalysts for automobile exhaust purification. Coating Al2O3 or SiO2 layer on the surface of ceria-zirconia solid solutions increased the specific surface area and thermal resistance. 展开更多
关键词 ceria-zirconia solid solutions oxygen storage materials rare earth doped catalysts
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Hydrothermal Synthesis and Characterization of Ce_(1-x)Mn_xO_(2-δ) Solid Solutions 被引量:1
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作者 张国芳 李莉萍 +1 位作者 李广社 邱晓清 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第2期307-313,共7页
Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11... Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11~15 nm.The incorporation of Mn ions in CeO2 resulted in a lattice volume reduction.Mn ions showed a mixed valence state of +2,+3 and +4 in CeO2 lattice.An obvious red-shift of the absorption threshold edge was observed from the UV-visible spectrum.Compared with the bulk CeO2,Ce1-xMnxO2-δ nanocrystals exhibited a lower releasing oxygen temperature as indicated by TPR technique. 展开更多
关键词 Mn doped solid solutions hydrothermal method valence state
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Synthesis and characterization of cadmium-calcium hydroxyapatite solid solutions
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作者 Xin Zhao Yi-nian Zhu Liu-qin Dai 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第6期604-608,共5页
A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges... A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard’s rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure. 展开更多
关键词 HYDROXYAPATITE solid solutions CADMIUM CALCIUM SUBSTITUTION
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Features of the Conductivity of the Ag8Ge1-xMnxTe6 Solid Solutions
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作者 Rashad Rahimov Aynur Gahramanova +2 位作者 Durdana Arasly Almaz Halilova Ilgar Mammadov 《Journal of Materials Science and Chemical Engineering》 2022年第5期16-28,共13页
Samples of Ag<sub>8</sub>Ge<sub>1-x</sub>Mn<sub>x</sub>Te<sub>6</sub> solid solutions with different manganese content (x = 0, 0.05, 0.1, 0.2) were prepared by fusing an... Samples of Ag<sub>8</sub>Ge<sub>1-x</sub>Mn<sub>x</sub>Te<sub>6</sub> solid solutions with different manganese content (x = 0, 0.05, 0.1, 0.2) were prepared by fusing and further pressing their powders under the pressure of 0.6 GPa. In addition of Mn atoms to the Ag<sub>8</sub>GeTe<sub>6</sub> compound leads to compression of their lattice. All p-type samples acquire a high resistance below the transition at temperatures of 180 - 220 K. The electrical conductivity of all compositions in the range of 220 - 300 K increases due to hopping mechanism, and at temperatures T > 320 K, a semiconductor characteristic is observed. By studying impedance spectra of samples, it was established that at 80 K solid solutions behave like a homogeneous dielectric material. At high temperatures and frequencies of an external electric field, a significant role of grain boundaries in conductivity was revealed. The dielectric anomaly occurring at low frequencies is also associated with an effect that manifests itself in the grain boundary. 展开更多
关键词 solid solutions X-Ray Diffraction Hopping Conductivity Electrical Conductivity Impedance Spectra
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Current Carriers Scattering in InP-InAs Solid Solutions
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作者 Nodar Kekelidze Elza Khutsishvili +2 位作者 Bella Kvirkvelia Gulnara Urushadze George Kekelidze 《Journal of Electrical Engineering》 2014年第2期86-91,共6页
Electrical parameters of n-type InPxAs1-x solid solution crystals have been investigated in the range of 4.2-300 K. Theoretical calculations of current carriers mobility have been carried out and they are in good agre... Electrical parameters of n-type InPxAs1-x solid solution crystals have been investigated in the range of 4.2-300 K. Theoretical calculations of current carriers mobility have been carried out and they are in good agreement with experimental results. The contribution of current carriers scattering main mechanisms has been determined. Comparison of experimental and theoretical data has shown minor contribution of disorder scattering associated with the disordered arrangement of atoms in InPxAs1-x solid solutions. Contribution of the disorder scattering increases with increasing of InP composition in solid solutions system at fixed temperatures and weakens with lowering of temperature and never dominates. A maximal share of the "alloy" scattering observed in experimental samples of lnPxAs1-x solid solutions differs from the similar scattering in SiGe alloys. It does not exceed - 20% of total scattering at 300 K and - 10% at lower temperature. A relative small contribution of disorder scattering is important for the devices designed on the base of InPxAs1-x system. 展开更多
关键词 InPxAs1-x solid solutions MOBILITY alloy scattering.
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Role of Microstructure and Spectrum Features on the Catalysis Effect of Ce1-x(Nd0.5Eu0.5)xO2-δSolid Solutions
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作者 张国芳 侯忠辉 +2 位作者 翟亭亭 许剑轶 张羊换 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第1期44-54,共11页
Nanosized Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions(x = 0.00-0.20) were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the... Nanosized Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions(x = 0.00-0.20) were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the Mg2Ni–Ni–5 mol% Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) composites.The structures and spectrum characteristics of the Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions catalysts were analyzed systemically.XRD results showed that the doped samples exhibited single phase of CeO2 fluorite structure.The cell parameters and cell volumes were increased with increasing the doped content.Raman spectrum revealed that the peak position of F^2g mode shift to higher wavenumbers and the peak corresponding to oxygen vacancies were observed distinctly for the doped samples.UV-Vis technique indicated that the absorption peaks of Eu^3+ and Nd^3+ ions appeared; the bandgap energy was decreased linearly.The electrochemical and kinetic properties of the Mg2Ni–Ni–5 mol% Ce1-x(Nd0.5Eu0.5xO2-δ composites were measured.The maximum discharge capacity was increased from 722.3 mA h/g for x = 0.00 to 819.7 mA h/g for x = 0.16,and the cycle stability S20 increased from 25.0%(x = 0.00) to 42.2%(x = 0.20).The kinetic measurement proved that the catalytic activity of composite surfaces and the hydrogen diffusion rate were improved for the composites with doped catalysts,especially for the composites with x = 0.16 and x = 0.20.The catalysis mechanism was analyzed from the point of microstructure and spectrum features of the Ce1-x(Nd0.5Eu0.5)xO2-δ solid solutions. 展开更多
关键词 hydrothermal method Ce1-x(Nd0.5Eu0.5)xO2-δ solid solutions Mg2Ni ball milling catalysis mechanism
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Structure, synthesis, and catalytic properties of nanosize cerium-zirconium-based solid solutions in environmental catalysis 被引量:20
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作者 Jixing Liu Zhen Zhao +1 位作者 Chunming Xu Jian Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第10期1438-1487,共50页
Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexib... Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexibility in their composition and structure.By partial metal(including rare earth,transition,alkaline earth or other metal)doping into CZO,the physicochemical properties of these catalytic materials can be controllable adjusted for the study of specific reactions.To date,nanosize CZO has been prepared by co-precipitation,sol-gel,surfactant-assisted approach,solution combustion,micro-emulsion,high energy mechanical milling,etc.The advent of these methodologies has prompted researchers to construct well-defined networks with customized micromorphology and functionalities.In this review,we describe not only the basic structure and synthetic strategies of CZO,but also their relevant applications in environmental catalysis,such as the purification for CO,nitrogen oxides(NOx),volatile organic compounds(VOC),soot,hydrocarbon(HC),CO2 and solid particulate matters(PM),and some reaction mechanisms are also summarized. 展开更多
关键词 Cerium-zirconium solid solution SYNTHESIS Method STRUCTURE Environmental catalysis
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SnO_2-based solid solutions for CH_4 deep oxidation: Quantifying the lattice capacity of SnO_2 using an X-ray diffraction extrapolation method
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作者 孙琪 徐香兰 +5 位作者 彭洪根 方修忠 刘文明 应家伟 余帆 王翔 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1293-1302,共10页
A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M (M=Mn, Zr, Ti and Pb) molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3+, ... A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M (M=Mn, Zr, Ti and Pb) molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3+, Zr4+, Ti4+and Pb4+cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4+cations in the lattice can be maximally replaced by Mn3+. If the amount of Mn3+cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species. 展开更多
关键词 SnO2-based solid solution X-ray diffraction extrapolation method Lattice capacity Methane deep oxidation Carbon monoxide oxidation
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Synthesis and thermoelectric properties of Mg_2Si_(1-x)Sn_x solid solutions by microwave irradiation 被引量:4
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作者 周书才 白晨光 《Journal of Central South University》 SCIE EI CAS 2012年第9期2421-2424,共4页
In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx (x=0.2, 0.4, 0.6, 0.8) solid solutions, microwave irradiation techniques were used in pr... In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx (x=0.2, 0.4, 0.6, 0.8) solid solutions, microwave irradiation techniques were used in preparing them as thermoelectric materials. Structure and phase composition of the obtained materials were investigated by X-ray diffraction (XRD). The electrical conductivity, Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K. It is found that Mg2Si1-xSnx solid solutions are well formed with excessive content of 5% (molar fraction) Mg from the stoichiometric MgESil.xSnx under microwave irradiation. A maximum dimensionless figure of merit, ZT, of about 0.26 is obtained for Mg2Si1-xSnx solid solutions at about 500 K for x=0.6. 展开更多
关键词 Mg2Si1-xSnx thermoelectric material solid solution microwave synthesis
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Preparation and Characterization of Ce_x Th_(1-x)O_2 Solid Solutions Prepared by Sol-Gel Method 被引量:1
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作者 赵雷洪 罗孟飞 刘广宇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第2期251-253,共3页
The Ce_xTh_(1-x)O_2 solid solutions were prepared by citrate sol-gel method,and their structure and reduction properties were studied. XRD shows that solid solution with cubicphase formed in all the solid solutions (x... The Ce_xTh_(1-x)O_2 solid solutions were prepared by citrate sol-gel method,and their structure and reduction properties were studied. XRD shows that solid solution with cubicphase formed in all the solid solutions (x = 0.2, 0.5, 0.8) Ce_xTh_(1-x)O_2. Raman spectrum showsthat Ce-Th complex oxides can promote the formation of oxygen vacancies. Two reduction peaks appearin the TPR profiles of Ce_xTh_(1-x)O_2 solid solution. The a peak is attributed to the reduction ofCe^(4+) on the surface, and the β peak is attributed to the reduction of bulk CeO_2. Theincorporation of Th atom into CeO_2 improves the reduction of CeO_2. Ce_xTh_(1-x)O_2 mixed oxidesare promising materials for oxygen vacancies produced, as well as catalysts for many reactionsinvolved oxygen, such as the catalysts for three-way reactions for reducing the releasing pollutantsor combustion of VOCs. 展开更多
关键词 catalytic chemistry Ce_xTh_(1-x)O_2 solid solution reduction properties rare earths
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Electronic and thermoelectric properties of Mg2GexSn1-x(x=0.25,0.50,0.75) solid solutions by first-principles calculations 被引量:1
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作者 李开跃 鲁勇 +1 位作者 黄艳 邵晓红 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期280-287,共8页
The electronic structure and thermoelectric(TE) properties of Mg2GexSn1-x(x = 0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special qu... The electronic structure and thermoelectric(TE) properties of Mg2GexSn1-x(x = 0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special quasi-random structure(SQS) is used to model the solid solutions, which can produce reasonable band gaps with respect to experimental results.The n-type solid solutions have an excellent thermoelectric performance with maximum zT values exceeding 2.0, where the combination of low lattice thermal conductivity and high power factor(PF) plays an important role. These values are higher than those of pure Mg2Sn and Mg2Ge. The p-type solid solutions are inferior to the n-type ones, mainly due to the much lower PF. The maximum zT value of 0.62 is predicted for p-type Mg2Ge(0.25)Sn(0.75) at 800K. The results suggest that the n-type Mg2GexSn1-x solid solutions are promising mid-temperature TE materials. 展开更多
关键词 solid solution electronic structure thermoelectric transport property
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Composition-tunable ZnS1-xSex nanobelt solid solutions for efficient solar-fuel production
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作者 Pan Li Sajjad Hussain +2 位作者 Lu Li Lingju Guo Tao He 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第10期1663-1673,共11页
Band engineering based on the construction of solid solutions is an effective approach to enhance the efficiency of semiconductor photocatalysts, via which the balance between light absorption and driving force can be... Band engineering based on the construction of solid solutions is an effective approach to enhance the efficiency of semiconductor photocatalysts, via which the balance between light absorption and driving force can be well achieved by continuously tuning the band structure. Here the ZnS1–xSex nanobelt solid solutions have been prepared via thermal treatment of ZnS1–xSex(en)0.5 precursors. The compositions are adjusted by changing the mole ratio of Se to S powder in the starting materials, resulting in continuously modulating the alignment of energy levels of the obtained solid solutions. The band structure is also studied via theoretical calculation. Accordingly, the light harvesting can be tuned too, as confirmed by the UV-vis absorption spectra. XPS valence spectra are used to determine the valence band maximum. Transient photoluminescence spectra are employed to study the separation of photogenerated charge carriers. BET specific surface area and CO2 adsorption isotherms of different catalysts are measured. The obtained ZnS1–xSex nanobelts exhibit different photocatalytic activity for solar-fuel production, dependent on many factors like the light harvesting and alignment of energy levels. The related mechanism is studied in detail. 展开更多
关键词 ZnS1-xSex solid solution Band engineering Light harvesting Charge behavior Solar fuels
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Density Functional Theory and Electrochemistry Studies on LiFexMn1-xPO4 Solid Solutions
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作者 Kang-ping Wang Tao-tao Shen +1 位作者 Dong-ming Chen Wen-lou Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第6期687-692,I0002,I0013-I0015,共10页
The thermodynamic stability and lithiated/delithiated potentials of LiFexMn1-xPO4 were studied with density functional theorical calculations. The results show that the formation free energy of the LiFexMn1-xPO4 solid... The thermodynamic stability and lithiated/delithiated potentials of LiFexMn1-xPO4 were studied with density functional theorical calculations. The results show that the formation free energy of the LiFexMn1-xPO4 solid solution is slightly higher than that of the phase-separated mixture of LiFePO4 and LiMnPO4, and the two forms may co-exist in the actual LiFexMn1-xPO4 materials. The calculation manifests that the lithiated/delithiated potentials of LiFexMn1-xPO4 solid solutions vary via the Mn/Fe ratio and the spatial arrangements of the transition metal ions, and the result is used to explain the shape of capacity-voltage curves. Experimentally, we have synthesized the LiFexMn1-xPO4 materials by solid-phase reaction method. The existence of the LiFexMn1-xPO4 solid solution is thought to be responsible for the appearance of additional capacity-voltage plateau observed in the experiment. 展开更多
关键词 LiFexMn1-xPO4 solid solution solid state synthesis Density functional theory calculation Electrochemical performance
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Hierarchical Fe_(x)Bi_(2−x)S_(3) solid solutions for boosted supercapacitor performance
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作者 Fengming Zhou Xiaodong Wang +6 位作者 Ruijie Jing Xiaoyu Li Qi Zhang Zhenjiang Li Yunmei Du Zhenyu Xiao Lei Wang 《Nano Research》 SCIE EI CSCD 2024年第5期3997-4005,共9页
For the pursuit of high energy supercapacitors,the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial el... For the pursuit of high energy supercapacitors,the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial electric double layer capacitor(EDLC)type materials.Herein,a porous and defect-rich Fe_(x)Bi_(2-x)S_(3) solid solution structure is firstly constructed by employing Fe-doped Bi_(2)O_(2)CO_(3) porous nanosheets as a precursor,which presents dramatically increased energy storage performance than Bi_(2)S_(3) and FeS_(2) phase.For the optimized Fe_(x)Bi_(2-x)S_(3) solid solution(FeBiS-60%),the Fe solute is free and random dispersed in Bi_(2)S_(3) framework,which can effectively modulate the electronic structure of Bi element and introduce rich-defect due to the existence of Fe(II).Meanwhile,the FeBiS-60%,constructed by pore nanosheets that are assembled by self-supported basic nanorod units,presents rich mesoporous channels for fast mass transfer and abundant active sites for promoting capacity performance.Therefore,a high capacitance of 832.8 F·g^(-1) at a current density of 1 A·g^(-1) is achieved by the FeBiS-60%electrode.Furthermore,a fabricated Ni3S_(2)@Co_(3)S_(4)(NCS)//FeBiS-60%hybrid supercapacitor device delivers an outstanding energy density of 85.33 Wh·kg^(-1) at the power density of 0.799 kW·kg^(-1),and ultra-long lifespan of remaining 86.7%initial capacitance after 8700 cycles. 展开更多
关键词 SUPERCAPACITOR solid solutions defect structure hierarchical structure Bi_(2)S_(3)
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Multi-phase(Zr,Ti,Cr)B_(2) solid solutions:Preparation,multi-scale microstructure,and local properties 被引量:1
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作者 Laura SILVESTRONI Nicola GILLI +6 位作者 Alex SANGIORGI Alessandro COROZZI Suzana FILIPOVIĆ Nina OBRADOVIĆ Laia ORTIZ-MEMBRADO Emilio JIMÉNEZ-PIQUÉ William G.FAHRENHOLTZ 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第2期414-431,共18页
Multi-phase ceramics based on ZrB_(2),TiB_(2) and doped with CrB_(2) and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation ... Multi-phase ceramics based on ZrB_(2),TiB_(2) and doped with CrB_(2) and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex(Zr,Ti,Cr)B_(2) solid solutions.Core-shell structures formed in TiB_(2) grains,whereas ZrB_(2) appeared to form a homogeneous solid solution with the other metals.Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere.In addition,atomic size factors explicated the precipitation of CrB_(2) nano-particles into ZrB_(2)-rich grains and of ZrB_(2) nano-particles into TiB_(2)-rich grains.The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa. 展开更多
关键词 BORIDE CORE-SHELL solid solution NANOINDENTATION SINTERING
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Design of low-alloying and high-performance solid solution-strengthened copper alloys with element substitution for sustainable development 被引量:1
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作者 Jiaqiang Li Hongtao Zhang +2 位作者 Jingtai Sun Huadong Fu Jianxin Xie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期826-832,共7页
Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-... Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties. 展开更多
关键词 element substitution copper alloy solid solution strengthening microstructure and performance
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Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries 被引量:1
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作者 Xiang jun Pu Kunran Yang +6 位作者 Zibing Pan Chunhua Song Yangyang Lai Renjie Li Zheng‐Long Xu Zhongxue Chen Yuliang Cao 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期128-139,共12页
Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and on... Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs. 展开更多
关键词 extending solid‐solution range off‐stoichiometric Na_(3)Fe_(2.5)(P_(2)O_(7))_(2) sodium‐ion batteries structure-function relationship
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