长程有序的1-3型磁电复合纳米结构薄膜的构建与物性研究

项目名称： 长程有序的1-3型磁电复合纳米结构薄膜的构建与物性研究

项目编号： No.51202176

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 陆小力

作者单位： 西安电子科技大学

项目金额： 25万元

中文摘要： 1-3型复合纳米结构薄膜是一种纵向异质外延结构，它通过三维外延增加界面，减少衬底限制，提供有效的面外应力调控，是复合磁电体中非常重要的构型；对增强磁电耦合，提高临界温度有重要意义。然而其相分离的形成机理仍不清楚，其中各组分的形貌、尺寸、分布有序度强烈依赖于工艺条件且难以控制，这成为阻碍其应用发展的主要瓶颈。本项目针对这个问题，提出有序籽晶阵列调控复合材料中同质相成核生长的思路，将自发相分离变为诱导相分离，通过模板辅助的脉冲激光沉积技术，制备高度有序的外延籽晶纳米点阵，并在此基础上生长1-3型复合薄膜；探索不同尺寸，排列周期的籽晶对于体系相分离过程的影响，并研究相应的磁电耦合性质；有望制备出长程有序的1-3型复合磁电体，为揭示其相分离规律，实现材料组分、分布有序度的可控调制，继而从微观定量角度研究界面关联的磁电耦合特性提供实验基础。

中文关键词： 磁电耦合；籽晶诱导成核；有序相分离；纵向外延；核壳结构

英文摘要： The 1-3-type nanocomposite consists of two functional materials, the nanopillar arrays and the matrix, which is normally derived from spontaneous phase separation process. It was found that this vertical architecture can reduce the clamping effect from the substrate and maintain efficient strain coupling with large interfacial surface area and three dimensional heteroepitaxy. Motivated by recent progress about the switching of the magnetization on reversal of the ferroelectric polarization and highly enhanced Curie temperature in 1-3-type nanocomposites, it becomes a very hot system for the study of stain mediated magnetoelectric (ME) coupling. While the self-assembled growth mechanism of pillar in matrix architecture is not clear yet, and the size and degree of phase order among the nanopillars are uncontrollable and highly dependent on growth conditions. The open question now is how to induce long-range phase ordering in 1-3-type composite, so that one can quantitative control the interfacial area and strain. In this proposal, we introduce highly ordered seed arrays in the growth process of 1-3-type composite to confine the phase separation. As a example, CoFe2O4 dot arrays will be fabricated via a stencil-derived direct epitaxy technique, and CoFe2O4-BiFeO3 (CFO-BFO) composite films will be grown over these C

英文关键词： magnetoelectric coupling；seed nucleation-induced process；ordered phase separation；vertical epitaxial interface；core shell nanostructure