Annealing can increase the Curie temperature and net magnetization in uncapped (Ga,Mn)As films, effects that are suppressed when the films are capped with GaAs. Previous polarized neutron reflectometry (PNR) studies of uncapped (Ga,Mn)As revealed a pronounced magnetization gradient that was reduced after annealing. We have extended this study to (Ga,Mn)As capped with GaAs. We observe no increase in Curie temperature or net magnetization upon annealing. Furthermore, PNR measurements indicate that annealing produces minimal differences in the depth-dependent magnetization, as both as-grown and annealed films feature a significant magnetization gradient. These results suggest that the GaAs cap inhibits redistribution of interstitial Mn impurities during annealing.
@article{arxiv.cond-mat/0409270,
title = {Effects of Capping on the (Ga,Mn)As Magnetic Depth Profile},
author = {B. J. Kirby and J. A. Borchers and J. J. Rhyne and K. V. O'Donovan and T. Wojtowicz and X. Liu and Z. Ge and S. Shen and J. K. Furdyna},
journal= {arXiv preprint arXiv:cond-mat/0409270},
year = {2009}
}
Comments
12 pages, 3 figures, submitted to Applied Physics Letters