Magnetic properties of thin films of FeCuRSiB type alloys (R-rare earth)

Abstract
As a continuation of our investigation of FINEMET alloy thin films. Fe_23.5Cu₁Nb₃Si_13.5B₉, with Nb replaced by other high-melting metals W, Mo, Ta, V [1.5], in this work we report studies on the alloys in which these refractory elements were replaced by the following representatives of lanthanides : Yb, Ho, Tb, Gd, Sm, Nd, Pr an Y as en element without a magnetic moment [9]. Their structure was determined on the basis of electron diffraction studies and TEM observations. The structure of as-deposited films was found to be strongly dependent on the deposition conditions. The films deposited for less than 30 seconds were amorphous whereas those deposited for a longer time revealed microcrystalline structure (the temperature of the evaporation source was the same for all samples). The coercive field H_c in the film plane and the Hall extraordinary coefficient R₁ together with the value of magnetic saturation induction B, for the films of both types were determined from the magnetooptical Faraday effect and the Hall effect, respectively. A strong correlation between the magnetic behaviour and structural changes of the films was found, i.e., a strong increase in H_c and decrease in R₁ with increasing annealing temperature were observed.