应力对钙钛矿型过渡金属氧化物铁电、铁磁性质影响的研究

项目名称： 应力对钙钛矿型过渡金属氧化物铁电、铁磁性质影响的研究

项目编号： No.11474148

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 章维益

作者单位： 南京大学

项目金额： 80万元

中文摘要： 随着分子束外延、激光脉冲沉积和金属有机化学气相沉积等薄膜生长技术的日益成熟，研究具有结构类似但是物性互补的钙钛矿氧化物异质结和超晶格结构的新颖物性成为近年来的热门课题。通过选择不同的晶格失配和原子组分，各向异性应变不仅可以调控单一材料的铁电铁磁性质，更可以制备出单一材料所不具备的复合多铁物性。本项目采用第一性原理研究异质结材料和超晶格材料中外延应力导致的界面电子结构重整和切应力导致的中心反演对称破缺对材料电磁性质的调控。重点研究外延应力对铁电铁磁性质和磁电耦合性质的调控机制和切向应力对电极化的双势垒和磁晶各向异性能非对称性的影响。探讨多铁材料的优化设计和薄膜曲率与单向极化关系可能的器件应用。

中文关键词： 电子结构；第一性原理；表面和界面；磁电耦合

英文摘要： As the thin-film deposition methods, such as molecule beam epitaxy, pulsed laser deposition, and metal organic chemical vapor deposition, become mature technologies, exploring the novel functions of heterostructure and superlattice structures with similar crystal structures but different physical properties has attracted a great attention. By choosing crystals with different lattice mismatch and atomic compositions, anisotropic strain not only can manipulate the material properties of constituents, but also can create novel properties its constituents haven't. In this project, the first-principles method is used to study: (1) the impact of epitaxial strain on the reconstruction of interface structure and electronic structure. How these reconstruction processes mediate the coupling among constituent materials and affect the ferroelectric, ferromagnetic, and magnetoelectric properties of heterostructures and superlattice structures?(2) the effect of shear strain on the asymmetrical properties of double well potential of ferroelectrics and magnetocrystalline anisotropy energy of ferromagnets. How the curvature induced polarization and magnetization reversal of ferroelectrics and ferromagnet can be used for possible device purpose

英文关键词： Electronic structures;First principles;Surface and interface;Magnetoelectric coupling