一种新型颗粒结构微粉的制备与穆斯堡尔谱研究

Preparation and Mssbauer Studies of A New Recording Particles with Core/Shell Structure

采用特殊的氮化工艺 ,成功地制备出一种新型的、具有内核 (α- Fe)表层 (γ′- Fe4N)结构的磁性颗粒 ,这种颗粒结构的微粉既具有α- Fe的高饱和磁化强度又有γ′- Fe4N优异的化学稳定性 .将穆斯堡尔谱与磁测量等方法相结合 ,研究了制备条件与磁性的关系 。

The typical particles with the core (α Fe)/shell (γ′ Fe 4N) structure, which have the advantages of higher both σ s of α Fe and stability of γ′ Fe 4N, have been successfully prepared. We have illustrated the M[KG-4] o[DD(-1]¨ ssbauer spectra of samples containing different γ′ Fe 4N fractions, and presented their fitting results as well. According to the relative fractions of γ′ Fe 4N and α Fe in the particles of core/shell structure, the magnetic properties were estimated. The total σ s of the particles was obtained to be in the range of 120～180 emu/g by adjusting the core/shell ratio, in agreement well with the fitting results of the MS, and the coercivity was found to be 300～800 Oe by controlling the shapes of the particles.