Mechanism of Ti-rich grain boundary phase formation and coercivity reinforcement in Sm(Fe0.8Co0.2)11TiBx melt-spun ribbons.

The effects of boron doping on the microstructure and magnetic properties of Sm(Fe 0.8 Co 0.2) 11 TiB x melt-spun ribbons were investigated. At a quenching speed of 25 m/s, the Ti-rich grain boundary (GB) phase and more percent of SmFe 12 phase was formed in the sample with x = 0.25, which increase the coercivity from 3 kOe to 6 kOe and remanence from 61 emu/g to 75 emu/g. The Ti-rich grain boundary phase show TiFe 2 -type structure, in which the (02–1) plane spacing of the grain boundary phase is half that of the adjacent (020) plane spacing of ThMn 12 phase. Electron holographic analysis showed that the Ti-rich GB phase can reduce the magnetization coupling between the SmFe 12 main phase grains. This served as a guide for the further fabrication of the GB phase in SmFe 12 -based permanent magnetic materials with high magnetic properties. [Display omitted] [ABSTRACT FROM AUTHOR]