Anisotropic crystallization and magnetic properties of Fe-based amorphous alloys induced by ion inclined bombardment

The structures and magnetic properties of Fe73.5Si13.5B9Nb3Cu1 amorphous alloys after ion bombardment were investigated. The needle-like structure and granular structure nanocrystalline was respectively formed for the samples bombarded by ion beam at the incident angle of 75° and 90°, which was explained according to the crystallization and crystal growth under anisotropic stress produced by ion beam inclined bombardment. The ion beam inclined bombardment produced a compressive and parallel stress on the sample, the compressive stress promoted the nucleation by decreasing the critical nucleation free energy and the parallel stress caused the directional migration of atoms. Low incident angle ion bombardment only led to the structure relaxation, and high incident angle ion bombardment produced a large compressive stress on the sample, which then induced the crystallization of amorphous alloys. The anisotropic crystallization caused by ion beam inclined bombardment resulted in the increase of magnetic anisotropy and then improved the high-frequency properties.