Coercivity shifts in exchange-coupled amorphous TbFe double-layer films

Measurements of extraordinary Hall effect in amorphous TbFe double-layer films, which have a uniaxial anisotropy with the easy axis perpendicular to the film plane, were performed in order to study the magnetic switching behavior. The observed hysteresis loops were found to be shifted when only the lower coercivity layer was switched. The temperature dependence of the coercivities (switching fields) for each layer were found to exhibit an abrupt jump at the crossover point i.e. when one layer changed from having the higher to the lower coercivity and vice versa. The results are discussed in terms of exchange interaction between the layers.