无稀土高饱和磁化强度Fe16N2薄膜的制备与研究

This project intends to prepare high saturation magnetization and high anisotropy single-phase α''-Fe16N2 film or FeN film with high α''-Fe16N2 content using a reactive magnetron sputtering combining with post-annealing methods. The impact of the preparation conditions of types of substrate, substrate temperature, nitrogen flow rate, film thickness, and annealing temperature on the final structure and properties of the film will be systematically studied. Using X-ray diffraction, Transmission Electron Microscope, X-ray Photoelectron Spectroscopy, M?ssbauer Spectra and Vibration Sample Magnetometer characterization methods to character the structure, composition and magnetic properties of the α''-Fe16N2 film. The impact of doping elements, such as Co, Ni, Ti, on the microstructure and thermal stability of the film will also be researched; the sources and mechanism of high saturation magnetization will be indicated using theoretical simulation. The use of rare earth material will be greatly reduced if the magnetic energy product of this rare-earth-free material can be comparable to that of NdFeB material, which has great significance to the protection of rare earth resources. Therefore, this project has important scientific significance and application value.

本项目拟采用反应磁控溅射结合后退火的方法来制备高饱和磁化强度和高各向异性的单相α''-Fe16N2薄膜或高α''-Fe16N2含量的FeN薄膜。系统研究基片种类、基片温度、氮气流量、薄膜厚度、退火温度等制备条件对薄膜最终结构和性能的影响。运用X射线衍射仪、透射电镜、X射线光电子能谱、穆斯堡尔谱和振动样品磁强计等表征手段研究α''-Fe16N2薄膜的结构、组成和磁性。研究Co、Ni、Ti等掺杂元素对薄膜微观结构与热稳定性的影响；并结合理论模拟进一步弄清其高饱和磁化强度的来源和机制。如果制备出的这一无稀土α''-Fe16N2材料的磁能积可以与NdFeB相媲美，将可以大大减少稀土的用量，对保护稀土战略资源有重要意义。因此本项目研究有重要科学意义和应用价值。

α''-Fe16N2相具有高饱和磁化强度和大磁晶各向异性，为实现大的磁能积提供了条件，有望替代部分稀土永磁材料。本项目采用反应磁控溅射结合后退火的方法在玻璃基片上制备出高饱和磁化强度和高各向异性的α''-Fe16N2薄膜和α''-(FeCo)16N2薄膜。系统研究了制备条件对薄膜结构和性能的影响，发现Co的掺杂有利于α''相的生成，并得出其高饱和磁化强度的可能来源和机制。同时还以α''相为软磁层，具有大的磁晶各向异性的永磁王Nd2Fe14B为硬磁层，将α''相和Nd2Fe14B通过纳米耦合来获得大的磁能积，可以在满足使用需求的同时大大节省稀土用量。扩展了由它们组成的软硬磁交换复合薄膜微磁学模拟方面的理论工作。项目的研究成果为α''-Fe16N2这一无稀土永磁材料的应用提供一定的实验依据和理论指导。