Magnetic properties of Ni/Tb multilayers

Abstract Thin multilayer films of alternating ultrathin Ni and Tb layers ( t Ni =5…80 A, t Tb =30 A) were sputter-deposited at room temperature and magnetically characterised by temperature-dependent SQUID measurements and torque measurements at T =300 K. Despite of the multilayer structure of all samples and a transition of the microstructure of the Ni layers the measured spontaneous magnetic moment of all samples is explained by a band filling model in analogy to amorphous and crystalline NiRE alloys. The magnetic Ni moment is quenched by a successive filling of its 3d minority band by the 5d, 6 s conduction electrons of Tb. As long as the Ni moment is not zero an antiferromagnetic Ni–Tb coupling and a perpendicular anisotropy component appears. The corresponding results of structural investigations are given elsewhere J. Magn. Magn. Mater. 248 (2002) 181.