High-temperature coercivity and Kerr spectroscopy on MnBi Al multilayers

The magneto-optic properties of multilayered MnBi/Al films have been invest igated and compared to pure MnBi films. The Al interlayers act as diffusion barrier during the MnBi formation process leading to a reduced MnBi partic le size of approximately 50 nm. The smaller particle size changes the domin ant magnetization reversal process from domain wall movement towards cohere nt rotation. This leads to a suppression of the anomalous increase of the h igh-temperature coercivity observed in pure MnBi. The comparison of the exp erimental polar Kerr spectra with theory elucidates the role of oxygen in M nBi films. (C) 1999 Published by Elsevier Science B.V. All rights reserved.