钙钛矿结构 SnTiO3铁电相变的第一性原理研究∗

摘要

Due to their spontaneous polarizations, ferroelectric materials have excellent dielectric, piezoelectric, pyroelectric properties, which enable them to be employed in many applications, such as capacitors, filters, sensors, detectors, and transducers, etc. In this paper, we use a first-principles-based effective Hamiltonian method to investigate perovskite SnTiO3, obtain essential coefficients for the effective Hamiltonian via ab initio computations, which are used in subsequent Monte-Carlo simulations to predict the phase transition temperature of SnTiO3, and different structural phases involved in such phase transition.%铁电材料因其自发极化而表现出优异的介电、压电、热电等性能，可用于电容器、滤波器、传感器、探测器、换能器等多种应用途径。本文利用有效哈密顿方法和基于密度泛函理论的第一性原理计算对钙钛矿结构SnTiO3进行了研究，计算获得了 SnTiO3的有效哈密顿量系数。利用这一结果，通过蒙特卡罗模拟，预测了SnTiO3的相变温度和参与相变的结构相。