多铁性六角铁氧体（MH）材料具有丰富的磁学和电学性质。目前MH材料的研究集中在块材和少量的薄膜材料方面。研究结果表明MH薄膜的磁学和磁介电效应与块材有一定区别。那么当我们进一步减小MH的三维尺寸和改变其形状时，纳米尺寸效应和形状各向异性等对MH的磁学和磁电耦合性质有什么影响？能否实现在微纳米尺度对MH材料电磁性质的多场调控？我们的初步研究结果表明，仅减小MH薄膜的厚度，薄膜的磁性质就有显著的变化。因此，本项目拟利用脉冲激光沉积和微纳加工技术制备MH有序微纳米单元阵列，首先研究纳米尺寸效应、形状各向异性和微纳单元间的偶极相互作用对微纳单元的多铁性温度转变点、磁性质（包括超顺磁尺寸和斯格明子等磁畴特征）和磁介电效应的影响，其次研究外加电场对微纳单元的磁特性和图形化阵列整体电磁性能的调制特征，最后建立微磁学模型和等效电路模型分析实验结果，探索MH微纳结构在多场调控微纳自旋电子器件中的应用潜力。

There are rich magnetic and electric phenomenon in the multiferroic hexaferrites（MH）. The reported studies on MH concentrate mainly on the bulk materials and a few thin films. Results show that there are some differences between the magnetic and magnetodielectric properties of the bulk material and the thin film. When the size of the MH material was further reduced and the shape was changed, what will be the effects of nano-size and the shape anisotropy on the magnetic and magnetoelectric properties of MH? Can we realize the multi-field manipulation of the electric and magnetic properties of MH at micro-nano scale? In order to answer the above two questions, we are going to fabricate the ordered MH micro-nano unit arrays. Firstly, we will investigate the effects of nano-size, shape anisotropy and inter-unit dipole interactions on the multiferroic transition temperature, magnetic (including superparamagnetic size, skyrmion domains et’al) and magnetodielectric properties of the MH. Then, we will investigate the effects of electric field on the magnetic properties of single MH unit and the electro-magnetic properties of the MH unit array. Finally, we will establish the micromagnetic and equivalent circuit models with the experimental parameters to analyze the results, and explore the application potentials of the MH micro/nanostructures in the novel multi-field controlled micro/nano-size spintronic devices.