TEMPERATURE-DEPENDENCE OF THE HYPERFINE FIELD DISTRIBUTIONS IN THE FE93.5-XNDXZR6.5 (X=0, 2) AMORPHOUS-ALLOYS

The 112 K spin-glass Fe93.5Zr6.5 and the reentrant Fe91.5Nd2Zr6.5 amor phous alloys have been studied at various temperatures with Mossbauer spectroscopy technique. At around T = 135 K for the Fe93.5Zr6.5 and at around T = 255 K for the Fe91.5Nd2Zr6.5, six broad lines appear, whic h are not well resolved. This broadening is ascribed to the magnitude distribution of the magnetic moments of the Fe atoms. From the fitting of the Mossbauer spectra at T = 4.2 K, the mean hyperfine field [H] a nd the Ecart-type standard deviation sigma(H) were estimated, and are (i) for the Fe93.5Zr6.5 sample, [H] almost-equal-to 205 kOe, and sigma (H) almost-equal-to 77 kOe; (ii) for the Fe91.5Nd2Zr6.5 sample, [H] al most-equal-to 228 kOe and sigma(H) almost-equal-to 70 kOe. These value s are found to be relatively consistent with the expected degree of ma gnetic frustration of the correspondingly Fe moments, according to the Fe content of these alloys.