R块外延生长S块与W型铁氧体的永磁特性

项目名称： R块外延生长S块与W型铁氧体的永磁特性

项目编号： No.51472004

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 刘先松

作者单位： 安徽大学

项目金额： 84万元

中文摘要： 由于W型铁氧体A2+Me22+Fe16O27具有高的饱和磁化强度和大的磁晶各向异性能，其作为永磁材料有着广阔的应用前景和巨大的潜在市场价值。本项目通过对W型铁氧体的离子取代，研究电子自旋和轨道的相互耦合下晶场效应对Me2+占据次晶位的影响。根据R块的六角对称性、超交换作用和单轴各向异性，外延生长具有立方对称的1/2尖晶石晶胞的2个S块。在单胞内，实现永磁相（R+S块）外延生长高饱和磁化强度的软磁相（S块）。通过组成、结构、晶粒优化，对磁矩取向、排布与单畴结构等进行有效的人为控制，以便设计出晶格匹配、单轴各向异性的W型铁氧材料。在一定温度梯度和外加磁场下，研究多晶W型铁氧体材料和晶界掺杂对永磁体的择优生长的影响，以制备出具有高剩磁和高内禀矫顽力的永磁体。因此，本课题提出R块外延生长S块与W型铁氧体的永磁特性的研究，不仅具有丰富的物理内涵，还拥有重要的应用价值，有望取得一些创新性的研究成果。

中文关键词： 磁性材料；铁氧体；W型；外延生长；永磁特性

英文摘要： W-type ferrite A2+Me22+Fe16O27, which possesses a high saturation magnetization and a large energy of magnetocrystalline anisotropy, have attracted a growing and widespread attention in the past decades due to their vast application prospect and huge potential market value.In this project, we explore a great deal of work on the research of the interactions of Me2+ occupied sites with crystal field effects under the coupling of electronic spin and spin-orbit, in which W-type ferrite has been substituted with multi-ion. The two S blocks, which have 1/2 spinel cell with cubic symmetry, are epitaxially grown on the R block according to its hexagonal symmetry, supper exchange and uniaxial anisotropy. As a result, a permanent magnetic phase (R block + S block) as M-type ferrite is stacked for a match by a soft magnetic phase (S block). We have given undivided attentions to its composition, structure, grain growth, the orientation of magnetic moment distribution and arrangement, single domain structure by some effective control in order to design a novel W-type ferrite with lattice match, which has a large uniaxial anisotropy. By manufacturing highly textured permanent magnets, which are parepred under a temperature gradient technique and an applied field, we resaerch the preferred growth W-type magnet through a polycrystalline material of W-type ferrite and grain boundary doping. With adjusting the crystallographical site occupied with different ions, saturation magnetization, magnetic anisotropy energy and magnet microstructure, it is hoped that the permanent magnet with a high intrinsic coercivity and a large remanence will be discovered. To sum up the points which we have just indicated, this project aims to research into the epitaxial growth of the S block on the R block and permanent magnetic properties of W-type ferrites, in which it not only has rich content of academic research, also has important practical value. Thus, it is expected to achieve a number of innovative research results.

英文关键词： magnetic material;ferrite;W-type;epitaxial growth;permanent magnetic properties