APPLICABILITY OF FMR FOR CRYSTALLIZATION STUDIES IN METALLIC GLASSES

It has been shown theoretically that the peak-to-peak ferromagnetic resonance (FMR) line-width (ΔHpp) should be proportional to the volume fraction (f) of the crystalline phase formed during annealing in ferromagnetic glasses. However, in the case of zero-magnetostrictive cobalt-based glasses (γ=0), ΔHpp should remain constant due to very low values of anisotropy. In Co68Fe4Mo1Si17B10 glass (γ=0), ΔHpp has been found to remain unaffected upon progressive crystallization. In Fe65Cr8B27 glass, ΔHpp has been found to be linearly proportional to f. Using this dependence, the activation energy of crystallization (Ea) has been calculated. The value of Ea obtained from the FMR technique (248 kJ mol-1) agrees quite well with those from DTA studies using Kissinger's or Ozawa's technique. © 1990 Chapman and Hall Ltd.