新型多铁材料SrMnO3薄膜的量子调控

项目名称： 新型多铁材料SrMnO3薄膜的量子调控

项目编号： No.11274194

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 于浦

作者单位： 清华大学

项目金额： 93万元

中文摘要： 近年来，多铁性材料及其磁电耦合效应因其蕴含的丰富物理和广阔应用前景而吸引了广泛关注。最近，第一原理计算和实验研究揭示了一类全新的单相多铁材料，AMnO3 (A=Ca, Sr, Ba)。因为自旋和声子的相互作用，该材料呈现出与磁序强烈耦合的铁电序。本课题将对应变SrMnO3薄膜中多铁序的量子调控进行系统研究。我们首先通过调节衬底与薄膜之间的应力来了解结构改变与晶格极化畸变的关联以及由此而产生铁电序的物理特性。我们将研究这个体系中的磁电耦合机制；既探索利用磁场控制介电和铁电性质以及利用应力或外加电场控制磁性的可能性。最后基于该模型系统，我们将对铁电畴壁等量子受限系统中的局域导电、磁阻效应等进行研究。我们预期本项研究将为多铁性研究开辟一个全新的道路。

中文关键词： 多铁；铁电；薄膜；；

英文摘要： During the past decade, multiferroics and related magnetoelectric coupling have attracted intense research interest in both condensed matter physics and materials science due to the wide range of physics insights and associated promising functionalities. Recently, First-principles calculations and experimental results on bulk single crystal have suggested a novel class of multiferroic materials, AMnO3 (A=Ca, Sr, Ba), which have strongly coupled ferroelectric and magnetic orderings due to the spin-phonon interaction. Here we propose a systematic study of the quantum manipulation of the multiferroic orderings in strained SrMnO3 thin films and related functionalities. Using epitaxial strain, we first investigate how the lattice structure can influence the polar instability through spin-phonon coupling, so as to induce ferroelectricity in this magnetic material. Detailed study of ferroelectric properties will be performed to understand the essential mechanism involved. Subsequently, we will study the magnetoelectric coupling in this single phase multiferroic by investigating the influence of magnetic phase transition as well as magnetic field perturbation on the dielectric and ferroelectric properties. We will also explore the possibility to manipulate the magnetic ground state through the epitaxial strain and/or t

英文关键词： multiferroic；ferroelectric；thin films；；