Magnetic behavior of thin rare-earth films

Abstract

We consider a thin rare-earth film with the c axis perpendicular to the surface, to study its nonuniform magnetic structure induced by the lower coordination near the surfaces. The influence of a dc magnetic field, applied perpendicular to the c axis, on the equilibrium configurations is also investigated. The spin-wave frequencies, in the q=0 limit, are calculated as a function of the strength of the external dc field. We use the bulk parameters of dysprosium and holmium to obtain the external field dependence of the equilibrium con- figuration, magnetization, and the lowest spin-wave modes of 30-monolayer-thick films.