Abstract A method is proposed for calculating the lattice parameter (l) for the solid solution (i.e. disordered binary substitutional alloy), which takes into account the pressure (P) in the alloy. An analytical expression is obtained for calculating the dependence of the function l on the alloy concentration at different values of P. It is shown that for P = 0 the deviation from the Vegard's law (Δl) is due to the difference in compressibility and in specific volumes of the pure crystals. The method is approved on SiGe, CuAu and AuFe alloys, and it was showed the good agreement with the experimental data. With an isothermal increase in pressure, the value Δl increases both for alloys with a negative and for alloys with a positive deviation from the dependence obtained by the Vegard's law. Calculations showed that for the SiGe alloy, the function Δl(P) passes over to the positive region at P0 = 0.685 GPa. It was shown the thermal expansion coefficient of a solid SiGe substitution solution at P = 0 deviates in the negative direction from the dependence that follows from the Vegard's law.

中文翻译：

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关于固溶体对 Vegard 定律的偏离

摘要 提出了一种计算固溶体（即无序二元置换合金）的晶格参数（l）的方法，该方法考虑了合金中的压力（P）。得到了一个解析表达式，用于计算不同 P 值下函数 l 对合金浓度的依赖性。 结果表明，当 P = 0 时，与 Vegard 定律 (Δl) 的偏差是由于可压缩性的差异和特定的纯晶体的体积。该方法在 SiGe、CuAu 和 AuFe 合金上得到认可，与实验数据吻合良好。随着压力的等温增加，对于具有负偏差的合金和对于具有正偏差的合金，Δl 值都增加，这与通过 Vegard 定律获得的相关性有关。计算表明，对于 SiGe 合金，函数 Δl(P) 在 P0 = 0.685 GPa 时传递到正区域。结果表明，在 P = 0 时，固​​体 SiGe 替代溶液的热膨胀系数与遵循 Vegard 定律的相关性在负方向上偏离。