Temperature induced interface roughness and spin reorientation transition in Co/Au multilayers thin films

Abstract

Spin reorientation transition (SRT) due to high temperature has been studied in Co/Au multilayered thin films. The effect of temperature on structural and magnetic properties of the thin films has been investigated. Film thickness and interface roughness has been studied by measuring x-ray reflectivity. Multilayers are thermodynamically stable, and thickness of the layers and interface roughness remains unchanged over longer periods of time as well as up to a temperature of 300 °C. An increase in interface roughness at higher temperatures indicates intermixing of Co and Au into each other. Behavior of coercive field for both the samples is quite different. However, the spin reorientation transition occurred in both the samples around 350 °C. Here we are reporting our study on temperature induced spin reorientation transition in Co/Au multilayers. A spin reorientation transition is observed from out-of-plane to in-plane direction for 12 Å thick Co layer sample at 350 °C and a reverse transition is observed for 25 Å thick Co layer sample. Results were obtained using ex situ and in situ Magneto-Optic Kerr Effect (MOKE) measurements.