Hydrogen absorption property and magnetism of SmFeAl and its hydrides

Magnetic properties of SmFeAl and its hydrides synthesized at 298–673 K under 40 bar hydrogen pressure were investigated by a superconducting quantum interference device (SQUID) from 4.2 to 300 K. SmFeAl and its hydrides have a mictomagnetic transition during the field-cooled process. In both SmFeAl and its hydrides, a shifted magnetic hysteresis cycle towards positive magnetization was observed. But when SmFeAlHx decomposes completely into SmHx and Fe–Al alloy, this special transition disappears.