EVOLUTION OF STRUCTURAL AND MAGNETIC-PROPERTIES IN TA NI81FE19 MULTILAYER THIN-FILMS/

The interdiffusion kinetics in short period (12.8 nm) Ta/Ni81Fe19 poly crystalline multilayer films has been investigated and related to the evolution of soft magnetic properties upon thermal annealing in the te mperature range 300-600-degrees-C. Small angle x-ray diffraction and t ransmission electron microscopy were used to estimate the multilayer p eriod. Interdiffusion in the multilayers was directly computed from th e decay of the satellites near (000) in a small angle x-ray diffractio n spectrum. A kinetic analysis of interdiffusion suggests that grain g rowth is concurrent with grain boundary diffusion of Ta in Ni81Fe19. T he evolution of soft magnetic properties of Ni81Fe19, i.e., lowering o f 4piM(s) and increase in coercivity H(c), also lend support to the ab ove analysis.