Perpendicular magnetic anisotropy of Tb-Co amorphous films sputtered in H2-added Ar gas

Abstract

Very large perpendicular magnetic anisotropy has been observed in Tb-Co amorphous films deposited by nonbiased rf sputtering using H2-added Ar gas. As the hydrogen partial pressure of the gas increases, the perpendicular anisotropy constant Ku increases remarkably and rectangular Kerr hysteresis loop appears. For 10% H2, Ku reaches near 105 J/m3, which is sufficient to direct the magnetization perpendicular to the film plane. These films can be used as magneto-optical recording media because of the relatively large Kerr rotation angle and coercive force. The mechanism of increasing Ku remains to be clarified.