Excellent magnetic softness in magnetostrictive TbFeCo/YFe multilayers

Abstract The {Tb(Fe 0.55 Co 0.45 ) 1.5 /Y 0.2 Fe 0.8 } 40 multilayers are investigated by X-ray diffraction and SQUID measurements. The results show that in the as-deposited multilayer, the TbFeCo and YFe layers are amorphous. An excellent magnetic softness with a coercivity of 0.3 mT was achieved after annealing at 250°C. These novel magnetic properties are associated to the evolution of a nanocrystalline structure in the YFe layers. Different temperature dependences of the coercive field are described for the amorphous and nanocrystalline multilayers.