物理合成纳米磁性颗粒的形状及感生各向异性研究

The magnetic nanostructual particle films with controlled particle size and excellent properties are manufactured by physical method condensed in inert gas enviroment. Unlike the traditional chemical syhthesis technique, in this application the magnetic nanosized particle beams are sputtered in torr-grade vacuum envrionment, and then transfered from lower vacuum chamber to higher one. This sputtering method promotes the deposition of gram magneitude magnetic nano-particles per hour. As for the potential high-frenquency application of our manufactured soft magnetic nano-particles with high magnetization, the project will focus on the exploration of many sputtering techniques, such as variable angle sputtering, composite sputtering, electric or/and magnetic field assisted sputtering ans so on. In this case, the shape and field induced anisotropys are persued in the synthesized magnetic particle films. Further more, the detailed design and manufacture of soft magnetic particle films with specific anisotropy and high homogeneity and density are perfobased on the thereotical modulation. The attention of high-frenquency magnetic properties are also paid to figure out the effect of the induce anisotropy on the high-f magnetic properties in the magnetic nano-particles. We believe that the project will pave the way to manufacture the soft magnetic nano-paricle films with specific shape and field induced anisotropy in controllable way.

利用惰性气体冷凝的物理方法制备尺寸可控、性能优异的磁性纳米颗粒薄膜。有别于传统湿化学合成技术,?本申请课题采用等离子体溅射惰性气体冷凝法将Torr量级下溅射出的磁性纳米颗粒束流由低真空腔靠阶梯压差沉积在高真空腔内的基片上,实现每小时克量级磁性纳米颗粒的沉积。鉴于所制备的高饱和磁感软磁颗粒具有潜在的超高频领域应用潜力，本项目拟结合变角度溅射、复合溅射、电场或磁场辅助沉积技巧等多种手段，深入研究这种物理方法合成的磁性纳米颗粒的形状及感生各向异性，结合微磁学理论计算设计和制备具有不同各向异性特征的高均匀性高致密度的软磁纳米颗粒薄膜，在此基础上探索该类薄膜材料的高频磁性，进一步从高频应用角度理解软磁纳米颗粒薄膜的各向异性对其高频磁性能的促进作用，为可控制备具有特定的形状及感生各向异性磁性颗粒薄膜奠定基础。

电子以及通讯工业的快速发展，电磁污染和电磁干涉会频繁充斥在日常生存空间中。近年来，无论是在军用和民用领域，对GHz范围内电磁波吸收材料的需求都日益增长。从电磁波的吸收机理来看，材料的吸波能力依赖于其本身的电磁特性。因此，该类功能材料的研究倾向于采用多元复合途径使其兼具磁-电的综合特性，以便于对材料的电磁性能进行有效调控。本面上基金主要利用自行搭建的高能纳米粒子沉积系统，在电场辅助沉积技术帮助下，合成了一系列FeNi和FeCoB纳米颗粒膜和多元复合薄膜，借助多种结构和磁性表征手段对材料的微观结构、软磁特性及其吸波性能进行研究，结果表明：..（1）适度施加辅助电场可以有效改善Fe50Ni50纳米颗粒膜的面内软磁性能，不同电场下将Fe50Ni50纳米颗粒沉积在Teflon上形成Fe50Ni50/Teflon复合材料，相同厚度情况下，较高的辅助电场制备条件有助于复合材料反射损耗峰由X频段向K频段方向移动。.（2）结合化学合成方法和电场辅助沉积技术制备了FeCoB/聚酰亚胺-石墨烯三元复合片层材料，研究发现石墨烯的添加可以显著影响聚酰亚胺-石墨烯的介电特性，沉积FeCoB颗粒，则有助于复合物电磁匹配特性的改善，反射损耗增加10 dB左右。.（3）在无外加磁场条件下，制备出高致密度图形化Fe50Ni50纳米薄膜。通过改变辅助沉积电场的大小，实现了图形化Fe50Ni50薄膜饱和磁化强度 和面内磁各向异性场的双提高。.（4）图形化FeCoB-SiO2纳米薄膜具有高电阻率、高饱和磁化强度、低矫顽力和合适大小的面内磁各向异性场，该设计使材料同时具有高磁导率和高电阻率成为可能。并且通过改变SiO2条纹宽度，在体积分数11~55%范围内，样品保持优异的微波磁特性。