标题： Pt$_{3}$Al在高压下具有L1$_{2}$结构的弹性和热力学性质的理论研究 显示英文标题

标题： Theoretical study of the elastic and thermodynamic properties of Pt$_{3}$Al with the L1$_{2}$ structure under high pressure

摘要： 在本工作中，使用广义梯度近似下的密度泛函理论研究了Pt$_{3}$Al在高压下的弹性及热力学性质。 零压下的体积模量和弹性常数结果与现有的理论和实验值有很好的一致性。 在高压下，所有的弹性常数都满足相应的机械稳定性准则，这意味着Pt$_{3}$Al具有机械稳定性。 此外，弹性常数和弹性模量随着施加的压力线性增加。 根据泊松比$\nu$和弹性模量比（$B/G$），发现Pt$_{3}$Al合金具有延展性，更高的压力可以显著增强其延展性。 这些表明，在高压下Pt$_{3}$Al的弹性性能将得到改善。 通过准谐波德拜模型，我们首次成功报道了德拜温度$\Theta_\textrm{D}$、比热容$C_{P}$、热膨胀系数$\alpha$和格鲁奈森参数$\gamma$在0到100 GPa压力范围和0到1000 K温度范围内的变化。 显示英文摘要

摘要： In this work, the elastic and thermodynamic properties of Pt$_{3}$Al under high pressure are investigated using density functional theory within the generalized gradient approximation. The results of bulk modulus and elastic constants at zero pressure are in good agreement with the available theoretical and experimental values. Under high pressure, all the elastic constants meet the corresponding mechanical stability criteria, meaning that Pt$_{3}$Al possesses mechanical stability. In addition, the elastic constants and elastic modulus increase linearly with the applied pressure. According to the Poisson's ratio $\nu$ and elastic modulus ratio ($B/G$), Pt$_{3}$Al alloy is found to be ductile, and higher pressure can significantly enhance the ductility. Those indicate that the elastic properties of Pt$_{3}$Al will be improved under high pressure. Through the quasi-harmonic Debye model, we first successfully report the variations of the Debye temperature $\Theta_\textrm{D}$, specific heats $C_{P}$, thermal expansion coefficient $\alpha$, and Gr\"{u}neisen parameter $\gamma$ under pressure range from 0 to 100 GPa and temperature range from 0 to 1000 K.