Magnetic Properties of Thin Films of Fe-Cu-R-Si-B Alloys with R = Nd, Gd, Ho, Y

Hysteresis loops of thin films of Fe$\text{}_{73.5}$Cu$\text{}_{1}$R$\text{}_{3}$Si$\text{}_{13.5}$B$\text{}_{9}$ (R = Nd, Gd, Ho, Y) alloys were studied by the magnetooptical Faraday method. The films were deposited by flash evaporation technique onto cooled glass substrates. Lanthanides were chosen as substitutes for niobium in the FINEMET type alloys. Coercivity, H$\text{}_{c}$, was determined from the easy- and hard-axis hysteresis loops. The as-deposited films containing Gd and Ho are characterized by rather low values of H$\text{}_{c}$ while the films with Nd and Y show a high isotropic value of H$\text{}_{c}$. Attempts were made to determine the conditions of the film annealing which would ensure the optimum soft magnetic properties of the films studied.