双钙钛矿Zn₂FeTaO₆电子结构和自发电极化的第一性原理研究

First-Principle Study of the Electronic Structure and Spontaneous Electric Polarization in Double Perovskite Zn₂FeTaO₆

摘要: 基于第一性原理方法，我们研究了双钙钛矿Zn₂FeTaO₆的晶体结构、电子结构、以及铁电性质。计算结果表明Zn₂FeTaO₆中的Zn²⁺离子，Fe³⁺离子和Ta⁵⁺离子均偏离氧八面体的中心。同时，基于线性响应理论Born有效电荷计算显示其自发电极化强度为79.6 μC/cm²。我们还利用杂化泛函理论进一步研究了Zn₂FeTaO₆的能带结构，发现带隙宽度约为2.6 eV，与多铁材料BiFeO₃接近，显示Zn₂FeTaO₆在铁电光伏领域的潜在应用。

Abstract: Based on density-functional theory, we have studied the crystal structure, electronic structure, and ferroelectric properties of double perovskite Zn₂FeTaO₆. It was revealed that Zn²⁺, Fe³⁺, and Ta⁵⁺ ions in Zn₂FeTaO₆ displaced away from the center of their oxygen octahedrons. With born effective charge from linear response theory, a large spontaneous electric polarization of 79.6 μC/cm² was found. Further calculations based hybrid functional show a band gap of around 2.6 eV, which is similar to BiFeO₃ and shows its potential application in ferroelectric photovoltaics.