Generic source of perpendicular anisotropy in amorphous rare-earth-transition-metal films.

Abstract

We show that the magnetic dipolar energy of antiparallel dipoles in the surface layers contributes to the intrinsic uniaxial perpendicular anisotropy in amorphous rare-earth-transition-metal films. The volume anisotropy energy density K u of this contribution depends inversely on the thickness of the film. For an amorphous GdCo film with a thickness of 1000 A the calculated K u is on the order of 10 3 -10 4 ergs/cm 3 . Dependence of K u on temperature and atomic concentration is also calculated