超高压下钙钛矿材料铁电峰值行为研究  

Ferroelectric Peak Behaviors of Perovskite Materials Under Ultra-High Pressure

作　　者：管豪毅 周志宏[1] 李亚兰[1] 梁英[1] 田晓宝 GUAN Haoyi;ZHOU Zhihong;LI Yalan;LIANG Ying;TIAN Xiaobao(College of Architecture&Environment,Sichuan University,Chengdu 610065,P.R.China)

机构地区：[1]四川大学建筑与环境学院,成都610065

出　　处：《应用数学和力学》2024年第10期1313-1319,共7页Applied Mathematics and Mechanics

基　　金：国家自然科学基金(12372154);国家重点研发计划(J2019-III-0010-0054);四川省科技计划(2024NSFSC0430)。

摘　　要：压力能够显著影响钙钛矿铁电材料的晶体结构和功能特性,且对相变温度的影响相对较小,是能比较有效地改善材料的介电和铁电性质的手段.该文利用基于第一性原理的分子动力学方法,探究了钛酸钡(BTO)单晶在常压至150 GPa静水压力区间的铁电性演变规律.结果表明,BTO单晶的铁电性随着压力的增加呈现出非单调的变化趋势,表现为先减弱、后增强,最后完全消失,并在42 GPa处出现峰值现象,其原因是压力导致的原子间距减小影响了长程Coulomb力与短程电子斥力的平衡.研究揭示的BTO单晶在超高静水压力环境下的铁电性变化规律,为未来钙钛矿材料在器件领域中的应用提供了理论基础,并为实验领域研究BTO铁电性的超高压行为提供了理论指导.Pressure has significant influences on the crystal structures and functional properties of perovskite ferroelectric materials,but relatively minor impact on the phase transition temperature,and can serve as an effective means to enhance the dielectric and ferroelectric properties of these materials.Molecular dynamics simulations were conducted based on the first principles to explore the evolution of ferroelectricity in barium titanate(BTO)single crystals subjected to hydrostatic pressures ranging from the atmospheric pressure to 150 GPa.The findings demonstrate that,a non-monotonic trend of the ferroelectricity of BTO occurs with the increase of the pressure.The ferroelectric first weakens,then intensifies,and finally disappears,with a peak at 42 GPa.This behavior can be attributed to the pressure-induced reduction in atomic spacings.This reduction disrupts the delicate balance between long-range Coulomb forces and short-range electron repulsions.The findings elucidate the ferroelectric behavior of BTO single crystals under ultra-high hydrostatic pressure,providing a theoretical foundation for their future applications to devices and offering valuable theoretical guidance for experimental investigations of BTO ferroelectricity under ultra-high pressures.

关 键 词：分子动力学 BTO 超高压 铁电性 

分 类 号：O32[理学—一般力学与力学基础] O521[理学—力学]