Enhancement of perpendicular anisotropy in amorphous GdCo and TbFe films prepared by alternative bias sputtering

Abstract

Amorphous GdCo and TbFe films were prepared by a newly devised sputtering technique in which film deposition and ion bombardments were performed alternatively. The changes of the film composition and magnetic properties were focused as a function of the thickness of the layer periodically deposited. It was found that ion bombardments induced by the substrate bias changed the composition only within a few atomic layers near the film surface. At the periodic thickness of about 3 nm, the enhancement of a perpendicular magnetic anisotropy took place in the both cases of GdCo and TbFe films. The new class of perpendicular anisotropy was discussed in relation to the multilayered structure formed by the alternative bias sputtering.