Magnetic studies of spin wave excitations in Ni/Au multilayers

Ni/Au multilayers were prepared by the electron beam evaporation method under ultra high vacuum conditions. The multilayer films have a coherent structure with (111) texture. The magnetic properties of Ni/Au multilayers are examined as a function of Ni layer thickness t(Ni). The temperature dependence of the spontaneous magnetization M(T) is well described by a T-3/2 law in all multilayers. A spin wave theory has been used to explain the magnetization versus temperature. Based on this theory, the approximate values for the bulk exchange interaction J(b), surface exchange interaction J(s) and the interlayer coupling strength J(l) have been obtained for various Ni layer thicknesses. (C) 2009 Elsevier B.V. All rights reserved.