Effect of a Buffer Permalloy Layer on the Structural State and Hysteresis Properties of FeNi/NiMn/FeNi Multilayer Films

Abstract

The crystal structure and hysteresis properties of FeNi/NiMn/FeNi multilayer films with varying composition of the NiMn layer (9, 27, and 49 at % Ni) and the thickness of the FeNi buffer layer (50–400 Å) preceding the NiMn layer are studied. In the films that have NiMn layers with 9 at % Ni, exchange bias is observed only in the lower layer, while in the films with 27 at % Ni, exchange bias is observed in both permalloy layers. It is established that the exchange bias field depends on the thickness of the buffer layer, and on the position of the permalloy layer in a film.