M. Farle et al., THE TEMPERATURE-DEPENDENCE OF MAGNETIC-ANISOTROPY IN ULTRA-THIN FILMS, Journal of magnetism and magnetic materials, 165(1-3), 1997, pp. 74-77
Results for the reorientation of the magnetization in 7.6 ML Ni(001)/C
u(001) as a function of temperature T are presented. The magnetocrysta
lline anisotropy coefficients up to fourth order are determined by in
situ UHV ferromagnetic resonance. The angle theta(eq) of the spontaneo
us magnetization measured from the film normal is found to change cont
inuously from 90 degrees at 200 K, i.e. in-plane, to 16 degrees at 250
K, to 0 degrees above 300 K. The unique reorientation of the magnetiz
ation to a perpendicular direction above a critical temperature T-R is
described quantitatively by the temperature dependence of the volume
and interface anisotropy contributions K-2(V) and K-2(S) which were al
so measured. This is compared with the case of Gd(0001)/W(110) and Ni(
111)/W(110). One finds that there is no universal behavior for the tem
perature dependence of K-2(V) and K-2(S) the case of Ni, the behavior
of K-2(V) is well described by a magnetoelastic model which uses only
the temperature dependence of the elastic and magnetostrictive constan
ts of bulk Ni and the lattice mismatch to the substrate.