TEMPERATURE-DEPENDENCE OF THE LOCAL MAGNETIZATION IN FERROMAGNETIC OVERLAYERS

The temperature dependence of the local magnetization in ferromagnetic overlayers is calculated in the spin-wave regime. Deviations of the i ntra-plane J(00) and interplane J(01) exchange integrals as well as of the spin S in the overlayer from their bulk values are considered. It is shown that an increase of the surface spin S has a similar effect on the temperature dependence of the surface magnetization M(S)(T) as strengthening of J(00). Calculations of M(S)(T) are also performed for different crystal orientations of the surface. It is found that M(S)( T) obeys a Bloch T-3/2 law with a prefactor that depends strongly on t he surface orientation.