Abstract
MnBi-LTP bulk magnets containing substitutional Sb element were fabricated using gas-atomizing process, surfactant-assisted wet magnetic compaction process, and thermal compaction process. Magnetic properties and microstructures were investigated according to the processing parameters. It was found that substitutional Sb element effectively refined the grain size of gas-atomized powders. The conventional ball milling process was able to pulverize these powders into fine particles with a single crystalline structure and minimize their phase decomposition, resulting in a (BH)max of 11.0 MGOe. By analyzing the effects of the compaction pressure on the density and magnetic alignment during the surfactant-assisted wet compaction process, Mn54Bi45.9Sb0.1 bulk magnet with Hc of 10.0 kOe at room temperature and temperature coefficient Hc of 0.68%/K was successfully fabricated. Furthermore, effects of Sb element on the temperature dependency of Hc in the bulk magnet were discussed.
NSTL
Elsevier