Evolution from soft to hard magnetic bahaviour in Co-based devetrified glassy alloy

From the amorphous alloy 6030V having the composition Co71.5Fe1.5Mo1Mn4Si 13B9, a series of devitrified specimens with increasingly coarser microstructure and magnetic hardening is produced by annealing. From the features of the coercivity, the squareness ratio, the rotational hysteresis integral, and the magnetic interactions we infer that the magnetic hardening is due initially (TA<600 °C) to a strengthening of the pinning effect of the precipitates on the domain walls, and then (Ta<600 °C) to the formation of single-domain Co crystallites where the magnetization reversal mode is of incoherent type. © 1996 American Institute of Physics.