复合掺杂铁氧体纳米材料的电磁性能调控及其变温穆斯堡尔谱研究

In this project, transition metal/rare earth ions doping process was used to design structure of soft magnetic ferrite nanocomposite, and moreover, nano-size controlled preparation based on soft chemistry method（Sol-Gel Auto Combustion, SGAC） was established and improved. The influences of microstructure, mechanical property, doping solid solubility, doping phase, size and shape of particles of transition metal/rare earth ions doped soft magnetic ferrite nano-composite on electromagnetic property of material, as well as the interrelation of these performance, are investigated. Through characterization of magnetization curve, susceptibility, resistance of nanomaterial, as well as measurement the relations of complex permeability, complex permittivity with frequency and temperature, the quantitative or semi-quantitative relationship between coupling strength resulted from magnetic exchange interaction of nano material and stoichiometric ratio of doped or substituted transition metal/rare earth ion was set up. Simultaneously, theoretic analysis about interaction of magnetic performance modified by doping process was accomplished. To improve properties of nanocrystalline ferrite materials, especially the structure under the condition of high temperature and magnetic properties of stability.Our work would lay the foundations for control on magnetic property of ferrite nano-composite doped by transition metal/rare earth ion, furthermore, to improve service performance of soft magnetic ferrite nanocomposite.

本项目拟采用过渡金属/稀土离子掺杂改性，对纳米复合软磁铁氧体材料结构设计，建立并完善基于软化学方法（溶胶凝胶自蔓延法Sol-Gel Auto Combustion, SGAC）的纳米尺寸可控制备技术。研究过渡金属/稀土离子掺杂纳米复合软磁材料的微观结构、力学性能、掺杂固溶度、掺杂复合相以及材料的颗粒尺寸形状与材料电磁性能的关系，以及它们之间的相互关联。通过表征纳米材 料的磁化曲线、磁化率、电阻率，测量磁导率、复介电常数与频率和温度的关系等磁性/介电性质，建立纳米尺寸下材料磁性交换相互作用的耦合强度与掺杂或替 换过渡金属/稀土离子化学计量比的定量或半定量关系，并完成掺杂改性的磁性相互作用模型的理论分析。提高纳米铁氧体材料使用性能的途径,尤其是其在高温条件下结构和磁性能的稳定性等。为实现过渡金属/稀土离子掺杂对复合纳米铁氧体材料的电磁性能调控，提高复合软磁纳米材料使用性能奠定基础。

本项目利用磁性测量与变温穆谱测量来探索磁性功能纳米材料的磁化规律和磁晶各向异性，为掺杂离子的挑选和掺杂量提供理论依据，并能实现对磁性功能纳米材料电磁性能的掺杂调控，通过研究纳米尺度下材料的功能材料磁相互交换作用与掺杂化学计量关联度，通过微观结构、磁性介电性能表征，找出不同掺杂材料的磁性、电阻率、阻抗、损耗物理参量调控规律，设计具有应用价值磁性功能纳米材料。