Coercivity and microstructure of melt-spun Sm(Fe11Ti)

Abstract

Amorphous Sm(Fe11Ti) ribbons were prepared by melt spinning. After heat treatment, very fine grains (≊50 nm) of the ThMn12-structure phase were obtained with no signs of a separate intergranular phase. Each grain appears to be a single domain. The maximum room-temperature coercivity is 0.56 T, rising to 1.20 T at 11 K. A model is proposed for the coercivity which is based on an analogy with the random anisotropy model of amorphous magnetism. It gives the correct magnitude of the coercivity, and suggests it should vary as the reciprocal of the crystallite size.