Magnetic behaviour of some amorphous Er-Co alloys

Some amorphous Er-Co alloys, have been studied by examining their normal ma gnetization curves with both hysteresis major and minor loops. Rayleigh par ameters from hysteresis minor loops allowed to describe the low-field behav iour of the magnetization: (i) the increase of i:, is in a good agreement w ith 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 ra tio alpha H-c/chi(o) is close to 1 for the thin sample(0.1 mu m) as predict ed by the Neel theory. (C) 2000 Elsevier Science B.V. All rights reserved.