Experimental temperature dependence of the magnetization of surface layers of Fe at interfaces with nonmagnetic materials

Theoretical studies have investigated the temperature dependence of the magnetization at the surface of ferromagnets. For isotropic exchange uniform throughout the sample, the temperature dependence of the surface magnetization varies asM(T)/M(0)≈(1−BT3/2) with aB factor at least twice as great as the bulk value. For cases in which the exchange interaction is different in the surface layer, or in which there is a significant surface exchange anisotropy, a different temperature dependence may result. These theoretical results have seen little experimental test. We report here measurements made on epitaxial (110) Fe films in which different temperature dependences are found depending upon the interfacial material chosen as a covering layer.