INTERFACE EFFECTS ON THE CRITICAL-TEMPERATURE OF HETEROSTRUCTURES OF MAGNETIC-FILMS

The analytical approach to the critical point of Ising films proposed recently by Lin et al is extended to investigate the interface effects on the critical temperature T-c for magnetic bilayer heterostructures . We consider heterostructures composed of an m-monolayer film grown o n a substrate of an n-monolayer magnetic film with different lattice s tructures where 1 less than or equal to m and n less than or equal to infinity. The mean T-c(m, n) of the bilayered heterostructure as a who le is obtained as a function of the total thickness N = m + n of the i nhomogeneous system. A strong dependence of the critical temperature u pon the lattice structure is revealed. In particular, interface effect s on T-c for systems consisting of an overlayer of a few spin monolaye rs on a thin film of magnetic substrates with different lattice struct ure are investigated in detail and results for various combinations of the lattice structure are discussed.