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Antisite effect on ferromagnetism in (Ga,Mn)As

R. C. Myers·B. L. Sheu·A. W. Jackson·A. C. Gossard·P. Schiffer·N. Samarth·D. D. Awschalom
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Abstract

We study the Curie temperature and hole density of (Ga,Mn)As while systematically varying the As-antisite density. Hole compensation by As-antisites limits the Curie temperature and can completely quench long-range ferromagnetic order in the low doping regime of 1-2% Mn. Samples are grown by molecular beam epitaxy without substrate rotation in order to smoothly vary the As to Ga flux ratio across a single wafer. This technique allows for a systematic study of the effect of As stoichiometry on the structural, electronic, and magnetic properties of (Ga,Mn)As. For concentrations less than 1.5% Mn, a strong deviation from Tc ~ p^0.33 is observed. Our results emphasize that proper control of As-antisite compensation is critical for controlling the Curie temperatures in (Ga,Mn)As at the low doping limit.

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R. C. Myers, B. L. Sheu, A. W. Jackson, A. C. Gossard, P. Schiffer, N. Samarth, D. D. Awschalom. 2006-06-19. Antisite effect on ferromagnetism in (Ga,Mn)As. https://doi.org/10.1103/physrevb.74.155203

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