LiNbO3结构过渡金属氧化物的多铁性的第一性原理研究

项目名称： LiNbO3结构过渡金属氧化物的多铁性的第一性原理研究

项目编号： No.21303156

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： 徐源慧

作者单位： 燕山大学

项目金额： 25万元

中文摘要： 多铁材料具有重要的科学研究和技术应用价值。然而，至今被发现的多铁材料的数量仍十分有限，并且它们的物理机制还不是很清晰。本课题利用第一性原理不同近似方法（GGA、GGA+U、HSE杂化泛函）研究具有LiNbO3结构的过渡金属氧化物的多铁性，找寻具有更高铁电极化值和强磁电耦合的体系，同时探讨它们的铁电驱动机制和磁电耦合机制。此外，通过以过渡金属元素替代LiNbO3结构的ABO3构型铁电体中A位或者B位离子，从而实现极化结构和磁性离子相结合的潜在多铁体系，并理论预测它们的相稳定性和多铁性，同时为实验合成和新功能材料的设计提供理论依据。

中文关键词： 多铁性；过渡金属氧化物；LiNbO3结构；第一性原理计算；

英文摘要： Multiferroics represent an attractive class of compounds which combine rich and fascinating fundamental physics with a technologically appealing potential for applications. However, relatively few multiferroics have been identified, and in those that are known, the underlying mechanism is often controversial. In this work, by means of first-principles calculations within the GGA, GGA+U, and HSE functionals, we will investigate the multiferroic behavior in the known transition-metal oxides with the LiNbO3-type structure. The aim of our work is to search the multiferroic compounds with possibly high ferroelectric polarization and strong coupling between magnetism and ferroelectricity. Meanwhile, we will explore the mechanism driving the ferroelectricity and characterize the magnetic properties in those systems. Additionally, considering the fact that transition-metal oxides with a polar structure would be potential multiferroic candidates, we will attempt to theoretically predict new multiferroic materials by substituting transition-metal ions for the A (or B)-site atoms in ABO3-type ferroelectrics with the R3c symmetry. We hope that our results will not only expand our understanding on the multiferroic properties, but also provide a new avenue for synthesizing and designing novel multifunctional materials.

英文关键词： multiferroic；transition-metal oxides；LiNbO3-type structure；first-principles calculations；