Effect of Gd addition on the structural and magnetic properties of <i>L</i>1-FePt alloy thin films

The impact of Gd addition on the structural and magnetic properties L10-FePt alloy thin films, which were sputter-deposited MgO(001) substrates at 800°C, was investigated. A rapid deterioration L10 chemical ordering along with a strong amorphization effect is observed Gd. At more than 20 at. % Gd, additional crystalline phases occur. Due to diminishing order, perpendicular anisotropy (PMA) gets strongly reduced from about 3 down 1 MJ/m3 14 For higher concentrations, easy axis magnetization turns fully in-plane due dominating shape anisotropy. Furthermore, saturation antiferromagnetic coupling between Fe moments. Also, Curie temperature can be lowered. Interestingly, change in film morphology takes place, changing an isolated island structure continuous morphology, particular interest for samples low concentration as these films exhibit still PMA but rather coercive fields.