Magnetic Properties of Al/Tb-Fe-Co Multilayer Thin Films

Abstract

A series of periodic multilayer Al/Tb-Fe-Co thin films have been prepared by dc-magnetron sputtering. The films are of the form (xA/yB)n, where x and y are the thicknesses of the A and B layers respectively, and n is the number of bilayer units. Individual layers are from 2-40nm thick. The magnetic properties of the films have been measured as a function of Al and Tb-Fe-Co layer thicknesses by vibrating sample magnetometry (VSM). An homogeneous film of the Tb-Fe-Co alloy was grown under identical conditions and found to have in-plane easy magnetization. Pronounced interfacial and/or reduced dimension effects have been found in the multilayer systems. These include evidence for a “dead layer” in the interface regions (~2nm thick) and reversal of the direction of easy magnetization from in-plane (in the homogeneous thin film samples) to strongly perpendicular in the multilayer configuration.