High-pressure synthesis and energetics of MgCu with a CsCl-type structure
High-pressure synthesis and energetics of MgCu with a CsCl-type structure
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DOI：
10.1016/j.jallcom.2004.12.163
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发表时间：
2005-12
影响因子：
6.2
通讯作者：
H. Takamura;H. Kakuta;Y. Goto;H. Watanabe;A. Kamegawa;M. Okada
中科院分区：
文献类型：
--
作者：
H. Takamura;H. Kakuta;Y. Goto;H. Watanabe;A. Kamegawa;M. Okada
在高压下制备了具有cscl型结构的新型金属间化合物MgCu，并用密度泛函计算方法讨论了其生成焓等热力学性质。采用立方砧型装置，在800℃、6 GPa条件下制备了晶格常数为a=0.3161 nm的MgCu相。在第一性原理计算中，采用了全势线性化增广平面波（FPLAPW）技术。通过体积优化得到的晶格常数与观测值吻合较好，精度小于0.3%。根据总能量的计算，MgCu相的生成焓为−18.4 kJ/mol。此外，MgCu相在520 K左右分解为Mg2Cu和mgcu2相，ΔH=−2.2 kJ/mol（放热）。计算得到的ΔH（−6.4 kJ/mol）也与实测值吻合较好。
The novel intermetallic compound of MgCu with a CsCl-type structure has been prepared under high pressure, and its energetics including the enthalpy of formation has been discussed by means of density functional calculations. The MgCu phase with a lattice constant of a=0.3161 nm was prepared by using cubic anvil-type apparatus at 800 ° C under 6 GPa. For the first-principles calculation, a full potential linearized augmented plane wave (FPLAPW) technique was used. The lattice constant obtained as a result of volume optimization showed a good agreement with the observed value with an accuracy of less than 0.3%. From the calculation of the total energy, the enthalpy of formation of the novel MgCu phase was estimated to be − 18.4 kJ/mol. In addition, the MgCu phase decomposed into Mg2Cu and MgCu2phases at around 520 K with ΔH=−2.2 kJ/mol (exothermic). The calculated ΔH (− 6.4 kJ/mol) also showed a fairly good agreement with the observed value.