钙钛矿铁电材料中化学计量失配对铁电性和磁性的影响

项目名称： 钙钛矿铁电材料中化学计量失配对铁电性和磁性的影响

项目编号： No.11304158

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 郭艳艳

作者单位： 南京邮电大学

项目金额： 28万元

中文摘要： 调控钙钛矿铁电材料中铁电序与量子涨落的竞争一直是量子调控研究领域中的热点。先兆型铁电材料SrTiO3(STO)因其处于量子临界区域，故其中的铁电不稳定性对于内部或外部的微小扰动非常敏感，展现出了十分丰富的物理现象。本项目从一种调控STO铁电序的新方法-化学计量失配入手，着重研究化学计量失配对ABO3钙钛矿铁电材料中铁电性和磁性的影响。主要研究内容包括：(1)通过多重实验手段，深刻理解和完善与化学计量失配的STO中铁电性和磁性相关的反位缺陷理论；(2)拓展研究化学计量失配对非边缘型ABO3量子顺电体材料和传统ABO3铁电材料的影响及其中的物理机制；(3)探索影响磁性的各种可能因素，包括氧空位的影响；(4)设计同时具有良好铁电性和磁性的材料。本项目以实验探索为重点，结合理论计算，深入研究化学计量失配影响钙钛矿铁电材料铁电性和磁性的物理机制。本课题将完善和丰富铁电、磁性物理领域的研究。

中文关键词： 钙钛矿铁电材料；铁电性；氧空位；晶格畸变；磁性

英文摘要： The investigation on the modulation of the long-range ferroelectric order in competition with quantum fluctuations in ABO3-type perovskite ferroelectric materials has been always a hot topic in the fields of quantum manipulation. Incipient ferroelectrics SrTiO3(STO)is in the quantum critical regime, thus its FE instability hidden in the cloud of quantum fluctuations can occur against even weak intrinsic or external stimulus, which has been receiving great research attention due to rich physical phenomena. In this research project, we start with an alternative approach(nonstoichiometry)to modulate the ferroelectric instability in STO, and emphatically study the influence of nonstoichiometry on ferroelectricity and magnetism in ABO3-type perovskite ferroelectric materials. The primary contents are as follows:(1)thoroughly study and perfect the connection of the antisite-like defects and the ferroelectricity and magnetism in STO;(2)a further study on the influence of nonstoichiometry on ferroelectricity and magnetism in ABO3-type perovskite ferroelectric materials and the involved physical mechanism;(3)To further explore the various possible factors which may affect the magnetism, including the effect of oxygen vacancies on magnetism;(4)design high-performance materials exhibiting both spin and ferroelectric orders

英文关键词： perovskite ferroelectrics；ferroelectricity；oxygen vacancy；lattice distortion；magnetism