Temperature dependence of interface anisotropy in Ni/Mo multilayers

Equal layer thickness Ni/Mo multilayer samples ranging in Ni layer thickness d from 14 to 340 Å have been investigated by x-band ferromagnetic resonance at temperatures between 4 and 293 K. The dependence of anisotropy (less demagnetization) Ha upon d clearly indicates the interface anisotropy plays a significant role in these samples. Interface (Ks) and volume (Kv) contributions to the anisotropy are extracted at each temperature using an approximate form of Ha=2(Kv+2Ks/d)/M. The Ks temperature dependence is shown to be inconsistent with a simple mean field model and indicates that interface strain due to the Ni-Mo lattice mismatch is largely responsible for the origin of Ks.