正交钙钛矿锰氧化物薄膜多铁性调控的理论模拟研究

项目名称： 正交钙钛矿锰氧化物薄膜多铁性调控的理论模拟研究

项目编号： No.11204091

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 秦明辉

作者单位： 华南师范大学

项目金额： 25万元

中文摘要： 正交钙钛矿多铁性锰氧化物是第II类单相多铁材料的典型代表，因其丰富的物理性质和潜在应用前景成为近年来多铁研究的热点。尽管其走向实际应用主要是以薄膜异质结形式，但目前对锰氧化物薄膜多铁性的物理研究还非常稀少。本项目着重正交锰氧化物薄膜多铁性调控的理论模拟研究，在更宽参数范围内细致探究体系在外加磁场和电场下的多铁相图，特别关注衬底磁构型与晶格失配对薄膜多铁性的调控行为。此外，我们还将研究锰氧化物异质结的磁性质及探讨体系交换偏置的可能机制。本项目将以理论模型计算为重点，以深刻理解多铁相竞争和调控的物理机制为主线，以寻找更多更有效的多铁调控方法为目的，对正交钙钛矿锰氧化物薄膜和异质结的多铁性及调控行为进行深入研究。

中文关键词： 多铁氧化物；铁基超导体；失措体系；磁有序；相变

英文摘要： Orthorhombic perovskite manganites, typical representatives of type-II multiferroics, have recently attracted significant attentions due to the interesting physics and potential applications. Although the practical application of manganites mainly lies in thin films and heterostructures, there have been relatively fewer studies on the multiferrocity with this special geometry. In this project, we address the multiferroic behaviors in orthorhombic manganite thin films by theoretical simulations. In particular, multiferroic phase diagrams in larger regions of phase space along the magnetic and the electric field axes will be studied in details, and special attentions will be paid to the influence of substrate magnetic structures and lattice mismatch. In addition, the magnetic properties in manganites heterostructures will be studied, and related mechanisms for the exchange bias effect will be discussed. We should focus on theoretical model computations which will help us to get a deep understanding of the microscopic mechanisms of multiferroic phase competitions and manipulations. The multiferrocities in orthorhombic perovskite manganite thin films and heterostructures will be intensively studied to find more efficient manipulation methods in multiferroics.

英文关键词： multiferroic oxides；Iron-based superconductors；frustrated system；magnetic order；phase transition