Thickness dependence of magnetoelastic properties and of crystallization behavior in Fe-Tb-Dy/Fe and Fe-Tb-Dy/nanocrystalline Fe-Si-B-Nb-Cu multilayers

Fe-Tb-Dy/Finemet(TM) and Fe-Tb-Dy/Fe multilayers have been prepared by ion beam sputtering on room temperature sapphire substrates (Finemet is a nanoc rystalline Fe-Si-B-Nb-Cu magnetic alloy). After production, the Fe-Tb-Dy an d the Finemet layers are amorphous, whereas the Fe layers are polycrystalli ne. Subsequent annealing leads to relaxation of the amorphous Fe-Tb-Dy laye rs in both cases and to crystallization of the Finemet layers for the Fe-Tb -Dy/Finemet multilayers. In this regime, the properties of the multilayers can be well described by a mixture rule of the two perfectly coupled compon ents. In an optimum thickness range for both layers, they show very soft ma gnetic properties and high magnetoelasticity. Furthermore, it has been obse rved that crystallization of the Fe-Tb-Dy layers within the multilayer is h indered by interface stabilization as recently predicted in U. Herr, H. Gei sler, H. Ippach, and K. Samwer, Phys. Rev. B 59, 13719 (1999). (C) 2000 Ame rican Institute of Physics. [S0021-8979(00)09117-9].