Intercalation in the graphite-rubidium system under high pressure

Results of investigations on the graphite-rubidium system under high pressure (up to 25 kbar) are presented. In this system new graphite intercalation compounds of C_4.3−6.0Rb compositions have been obtained. These compounds have been shown to be unstable under normal conditions and to decompose to rubidium and less metal-saturated compounds when the pressure is reduced. The reaction is reversible - rubidium can be again intercalated into C₈Rb under high pressure at room temperature.     

稀土化合物应用于高能锂硫电池的研究进展

锂硫电池是极具开发潜力和应用前景的新一代高比能金属锂二次电池.拥有独特4f轨道的稀土元素及其化合物具有特殊的光、电、磁与催化等性质,研究发现将稀土化合物引入锂硫电池体系能够有效解决制约锂硫电池发展的穿梭效应和锂枝晶问题并显著提升电池性能.本文全面综述了稀土化合物应用于锂硫电池正极、隔膜和电解质的最新研究进展和动态及其解...     

IMEC—金属间化合物检索和预报的专家系统

采用化学键参数-模式识别方法总结的金属间化合物的形成、晶型和化学配比规律,建立了能检索、预报二元金属间化合物的专家系统——IMEC。可用人机对话形式提供任何二元合金系的金属间化合物的存在、晶型和化学配比的信息。     

IMEC——AN EXPERT SYSTEM FOR RETRIEVAL AND PREDICTION OF BINARY INTERMETALLIC COMPOUNDS

An expert system,IMEC,for the retrieval and prediction of binary intermetallic compoundshas been built.The rules found by chenlieal bond parameter-pattern recognition method havebeen used for computerized prediction.Data base of known mtermetallic compounds andchemical bond parameters of metallic elements and the knowledge proeessing system are included in the expert system.By man-machine interfacing,the formation,stoichiometry andcrystal type o fall binary intermetallic compounds can be predicted or retrieved.     

DRAWING PREDOMINANCE DIAGRAM OF M_1—M_2—x—y SYSTEM AND ITS APPLICATION

Discussions were made of the principle,method and computer program for drawing the pre-dominance diagrams of the bi-metal co-existed system M_1-M_2-x-y in which the multi-me-tallic compounds may be produced by interaction between compounds of both metals.Theformation of zinc ferrite and its stable region have been analyzed through drawingZn-Fe-S-O system predominance diagrams.The availability of the diagram is given the di-rection to roast the zinc sulfide ore as well.     

Phase diagram of the CsBr-CaBr2 system

The phase diagram of the CsBr-CaBr2 system was re-determined by using differential thermal analysis and high ternperature and room ternperature X-ray diffraction analysis. It is concluded that there are three intermediate compounds in this system： a.congruently melting compound, CsCaBr3, with a melting point of 823℃ and two incongruently melting compounds, Cs2CaBr4 and Cs3Ca2Br7, whose peritectic points being 597℃ and 635℃, respectively. X-ray diffraction analysis indicated that compound CsCaBr3 is of slightly distorted perovskite structure.     

Subsolidus phase relations in the ZnO–MoO3–B2O3, ZnO–MoO3–WO3 and ZnO–WO3–B2O3 ternary systems

The subsolidus phase relations in the ZnO–MoO₃–B₂O₃, ZnO–MoO₃–WO₃ and ZnO–WO₃–B₂O₃ ternary systems have been investigated by the means of X-ray powder diffraction (XRD). There is no ternary compound in all the systems. There are five binary compounds and five tie lines in the ZnO–MoO₃–B₂O₃ system. This system can be divided into six 3-phase regions. There are three binary compounds and three tie lines in the ZnO–MoO₃–WO₃ system. This system can be divided into four 3-phase regions. There are four binary compounds and four tie lines in the ZnO–WO₃–B₂O₃ system. This system can be divided into five 3-phase regions. The possible component regions for ZnO single crystal flux growth were discussed. The phase diagram of Zn₃B₂O₆–ZnWO₄ pseudo-binary system has been constructed, and the result reveals this system is eutectic system. The eutectic temperature is 1007 °C and eutectic point component is 70 mol% Zn₃B₂O₆.     

金属间化合物CePd5，PrPd5和NdPd5的晶体结构

稀土金属对富Pd合金的氢化性能、磁学性能和催化性能有显著的影响，对Pd-RE台金系中最富Pd的化合物的研究是有意义的。本工作通过恰当的熔炼和热处理工艺制备出单相的金属间化合物CePd5，PrPd5和NdPd5，并应用X射线衍射分析确定了它们的晶体结构和晶格参数。研究发现：在Pd-Ce二元系中，最富Pd的化合物是具有CaCu5型六方结构的CePd5；而在Pd-Pr和Pd-Nd二元系中最富Pd的化合物分别是具有SmPt5型正交结构的PrPd5和NdPd5。报道了经指标化的这3种金属间化合物的X射线衍射数据，确定CePd5的晶格参数a=0．5372nm，c=0．4178nm；PrPd5和NdPd5的晶格参数分别是a=0．5278nm，b=0．9239nm，c=2．575nm和a=0．5265nm，b=0．9219nm，c=2．570nm。并对Pd-RE合金系和Pt-RE合金系中最富Pd化合物的化学计量和晶体结构进行了对比。     

Thermodynamic Assessment of the Fe-Y System

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Thermodynamic calculation of intermetallic compounds in AZ91 alloy containing calcium

1 Introduction Magnesium alloy is regarded as a promising structural material in the 21 century because of its excellent properties such as low density, high specific strength, good castability and machinability[1?5]. The common magnesium alloy AZ91 is, however, unsuitable for using at the temperatures above 120 ℃ because of its poor creep resistance and strength at elevated temperatures[2]. Adding other elements, like calcium, is an important method to improve the mechanical properties of A…     

A thermodynamic analysis of the Al-Re system

Phase equilibria and thermodynamic data of the Al-Re system are critically reviewed. In addition to the three solution phases, liquid, fcc Al, and hcp Re, there exist six intermetallic compounds in this binary. The thermodynamic properties of the system are analyzed using thermodynamic models for the Gibbs energy of individual phases of the system. A regular solution model is used for the three substitutional solution phases, and the intermetallic phases are treated as stoichiometric compounds. The model parameters are optimized from a limited amount of experimental data. The calculated phase diagram and thermodynamic values are in accord with the available experimental values.     

Thermodynamic optimization of the Cu-Nd system

The thermodynamic constraints to eliminate artificial phase relations were introduced with the Cu-Nd system as an example. The enthalpies of formation of the compounds Cu₆Nd, Cu₅Nd, Cu₂Nd and αCuNd are calculated using density functional theory. Taking into account all the experimental data and the first-principles calculated enthalpies of formation of these compounds, the thermodynamic optimization of the Cu-Nd system was performed under the proposed thermodynamic constraints. It is demonstrated that the thermodynamic constraints are critical to obtain a set of thermodynamic parameters for the Cu-Nd system, which can avoid the appearance of all the artificial phase relations.     

Determination of isothermal sections of Ni-Cr-Nb ternary system

The isothermal sections of Ni-Cr-Nb ternary system at 1 323 K and 1 423 K were determined by means of diffusion triple and energy spectrum analysis (ESA). By analyzing the diffusion layers in the diffusion couples, the compounds forming in this system were identified. There are three similar compounds found at these two temperatures: Ni3 Nb, NiNb and NbCr2-R, and four similar three-phase regions are found : (Ni) (Cr) Ni3 Nb, Ni3Nb NbCr2-R NiNb, NbCr2-R (Cr) Ni3 Nb, NbCr2-R NiNb (Nb). The results show that no phase transformation happens between these tow temperatures. But the solid solubilities of the binary compounds at 1423 K become bigger than those at 1 323 K, especially the solid solubility of NbCr2-R. No ternary compound is observed.     

Cu与NbTi之间扩散反应的研究

采用电子探针微分析术研究了机械复合和冶金复合两种界面状态的Nb-Ti/Cu复合超导线,以及Nb-Ti/Cu,Ti/Cu和Nb/Cu偶的扩散反应过程.结果表明,原始组件的界面状态对Nb-Ti/Cu间金属间化合物的生成有明显的影响.机械复合组件较冶金复合组件能承受更高的热处理温度而不致生成金属间化合物.Ti与Cu之间反应生成化合物的次序与形态及NbTi与Cu之间不同.Ti/Cu间生成化合物的厚度y与时间t关系遵循y~(1.5-t)的规律.     

M_1-M_2-x-y系优势区相图的绘制及其应用SCIEI

本文讨论了双金属共存体系M_1-M_2-x-y,当两种金属的化合物相互作用生成多金属化合物时,优势区相图的绘制原理、方法及计算机程序。通过绘制Zn-Fe-SO系的优势区相图,分析了ZnO·Fe_2O_3的生成及稳定条件,并说明了其在硫化锌矿焙烧中的指导作用。     

Thermodynamic Assessment of Fe-Dy System

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Phase relations in the SrO–Ga2O3–B2O3 system

The subsolidus phase relations in the SrO–Ga₂O₃–B₂O₃ system were investigated. The system contains 10 binary compounds and two ternary compounds, and can be divided into 15 three-phase regions. The new ternary compound SrGaBO₄ has two modifications (- and β-phases), both of which crystallize in the orthorhombic system but with different space groups.     

Thermodynamic Assessment of Gd-Ni System

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KPO3—MoO3熔盐相图

用目测变温法及差热分析法测定了KPO3－MoO3体系熔盐相图，发现该体系生成两个化合物，它们的化学计量式分别为3KPO3·MoO3和KPO3·MoO3，经X射线衍射及Raman光谱分析得到进一步证实。     

ASSESSMENT OF THERMODYNAMIC DATA AND STABILITY OF INTERMETALLIC COMPOUNDS

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