Magnetic Studies of Spin Wave Excitations in Ni/Cu Multilayers

Abstract

The magnetic properties of Ni/Cu multilayers, prepared by the electron beam evaporation method under ultra high vacuum conditions, have been systematically studied by magnetic measurements. The temperature dependence of the spontaneous magnetization M (T) is well described by a T3/2 law. A spin wave theory has been used to explain the magnetization versus temperature. Based on this theory, the approximate values for the exchange interactions have been obtained

Thickness dependent Curie temperature and power-law behavior of layering transitions in ferromagnetic classical and quantum thin films described by Ising, XY and Heisenberg models

“…Fuchs et al [56,57] investigated the variation of magnetization as a function of film thickness for lanthanum films and extracted an exponent value λ = 0.9 which resembles a value obtained by MFT for Ising model. For ultra-thin nickel films, a shift exponent λ = 1.7 was found [58], and also a crossover from a three-to a two-dimensional magnetic behavior was observed by Li et al [59]. For thin iron films [60], phenomenological finite-size scaling analysis yields an effective shift exponent λ = 3.15 which is twice as large as the value expected from the conventional finite-size scaling prediction [51] whereas for amorphous iron and aluminum films [61] λ = 1.2 were found.…”