Résumé: Some amorphous Er:Co alloys, have been studied by examining their normal magnetization curves with both hysteresis major and minor loops. Rayleigh parameters from hysteresis minor loops allowed to describe the low-field behaviour of the magnetization: (i) the increase of [chi]m is in a good agreement with Rayleigh laws but a weak deviation is observed on the thick samples at fields up to 100 Oe, which can be due to magnetostatic effects; (ii) the ratio [alpha]Hc/[chi]0 is close to 1 for the thin sample (0.1 [mu]m) as predicted by the Neel theory.

Langue: Anglais