The effect of low-temperature annealing on ferromagnetic thin films studied by photoemission spectroscopyC. J. Ji1, H. T. He2, X. C. Cao1, K. Qiu1, F. Zhong1, X. H. Li1, Q. F. Han1, F. Q. Xu3, J. N. Wang2 and Y. Q. Wang1
1 Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences Hefei, Anhui, China
2 Physics Department, the Hong Kong University of Science and Technology - Clear Water Bay, Kowloon, Hong Kong, China
3 National Synchrotron Radiation Laboratory, University of Science and Technology of China - Hefei, Anhui, China
received 8 March 2007; accepted in final form 24 April 2007; published June 2007
published online 24 May 2007
A systematic photoemission and variable temperature resistivity measurements are carried out on Ga0.946Mn0.054As ferromagnetic semiconductors. It is showed that the Mn 3d valence band and the As 3d core-level spectrum are modified by the annealing treatment. Correlating these modifications with the observed changes in the resistivity and Curie temperatures, we have identified that the low-temperature annealing most likely induces three changes: interstitial Mn out-diffusion, slight increase of the substitution Mn components, and reduction of excess As.
75.50.Pp - Magnetic semiconductors.
© Europhysics Letters Association 2007