Electron transfer and novel magnetic behavior in hydrogenated FePd

Po-Chun Chang^1*, Wen-Chin Lin¹

¹Physics, National Taiwan Normal University, Taipei, Taiwan

* Presenter:Po-Chun Chang, email:chang155212@gmail.com

In this study, the magnetic moment of Fe in FePd alloy system was increased through hydrogen absorption, as confirmed by the enhanced X-ray magnetic circular dichroism (XMCD) signal of Fe. Hydrogen absorption and desorption hysteresis loop in the magnetic cercivity (H_c)-hydroge pressure(P_H2 ) diagram clearly proposed that hydrogen was absorbed at P_H2=100 mbar and desorbed at P_H2=10^-6 mbar in the FePd alloy film. The hydrogenation effect on magnetism of FePd alloy film could be eliminated by thermal effect. An elevated temperature (heating up 60 K) can recovered the magnetic behavior to the pristine situation before hydrogen absorption. The recovery of H_c is due to the competition between thermal activation and H-bonding, not caused by hydrogen desorption. These results clearly reveal the correlation between P_H2, temperature and the magnetic properties, and provide a typical hydrogenation effect on magnetic properties for future applications.

Keywords: Magnetic Domains, XMCD, FePd Thin Films, Hydrogenation Controlled Magnetism