Systematic investigation on the influence of the As4 flux on the magnetic property of (In,Cr)As quantum dotsH. J. Meng, J. Lu, S. Yan, P. H. Tan and J. H. Zhao
State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences - P.O. Box 912, Beijing 100083, China
received 8 August 2008; accepted in final form 30 October 2008; published December 2008
published online 12 December 2008
We study the structure, optical and magnetic characteristics of self-assembled (In,Cr)As diluted magnetic semiconductor quantum dots as a function of the As4 flux. Increasing the surface energy by increasing the As4 pressure leads to a smaller number of larger dots for a higher As4 flux. The remanent magnetization measured at 5 K also increases with increasing As4 flux, which is attributed to the enhancement of the effective Cr content due to the As4-rich condition. We explore the possibility of tailoring magnetism by controlling the As4/In flux ratio without changing the Cr concentration. Furthermore, extremely low-density QDs have also been successfully grown.
81.05.Zx - New materials: theory, design, and fabrication.
75.50.Pp - Magnetic semiconductors.
81.15.Hi - Molecular, atomic, ion, and chemical beam epitaxy.
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