Abstract

Herein, we report our density functional theory calculations for structure, electronic, thermodynamic and mechanical properties of MBiO₃ (M = Rb, Cs, Tl), compounds of perovskites oxide family. Exchange-correlation potential was treated with generalized gradient and local density approximations. From available ionic data, the tolerance factors and lattice constants were calculated. The values of tolerance factors provided the stability guarantee of MBiO₃ compounds in cubic phase while the obtained lattice constants are in accordance to the available data. The cubic phase stability was further confirmed from elastic constants. The electronic structure results disclosed these materials as metallic. Mechanically, all the three perovskites were found as brittle from Cauchy’s pressure, Pugh ratio and Poisson’s ratio. The thermodynamic calculations have been performed using quasi-harmonic Debye model. Thermal properties like Debye temperature, specific heat capacity and thermal expansion have been presented with the variation of temperature and pressure.

Graphical abstract

中文翻译：

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铋基氧化物钙钛矿MBiO 3（M = Rb，Cs，Tl）的结构，电子，机械和热学性能研究

摘要

本文中，我们报告了钙钛矿氧化物家族化合物MBiO ₃（M = Rb，Cs，Tl）的结构，电子，热力学和机械性能的密度泛函理论计算。交换相关势用广义梯度和局部密度近似处理。从可用的离子数据中，计算出公差因子和晶格常数。公差因子的值提供了MBiO ₃的稳定性保证化合物以立方相形式存在，而获得的晶格常数符合现有数据。由弹性常数进一步证实了立方相的稳定性。电子结构结果表明这些材料为金属。在机械上，从柯西压力，普格比和泊松比中发现所有三种钙钛矿都是脆性的。热力学计算已使用准谐波德拜模型进行。随着温度和压力的变化，已经呈现出诸如德拜温度，比热容和热膨胀之类的热特性。

图形概要