Hysteresis loop shift behavior of CoFeSiB amorphous ribbons

Exchange bias phenomena of amorphous CoFeSiB ribbons have been probed at room temperature. The dramatic loop shift away from zero point occurred when the ribbons were annealed in ambient atmosphere with longitudinal field. The possible crystalline phases grown in our ribbons are discussed based on the grazing incidence diffraction and energy dispersive x-ray spectroscopy. The magnetic domain configuration of ribbon surface was also observed to make clear the dependence of bias behavior on the induced magnetic anisotropy in the ribbon. A simple phenomenological explanation was given to discuss the exchange bias in ribbons.