Title :
Growth Parameter Dependence of Structural Characterizations of Diluted Magnetic Semiconductor (Ga, Cr)As
Author :
Lu, J. ; Bi, J.F. ; Wang, W.Z. ; Gan, H.D. ; Meng, H.J. ; Deng, J.J. ; Zheng, H.Z. ; Zhao, J.H.
Author_Institution :
Inst. of Semicond., Chinese Acad. of Sci., Beijing
Abstract :
We report the influence of growth parameters and post-growth annealing on the structural characterizations and magnetic properties of (Ga, Cr)As films. The crystalline quality and magnetic properties are sensitive to the growth conditions. The single-phase (Ga, Cr)As film with the Curie temperature of 10 K is synthesized at growth temperature Ts = 250degC and with nominal Cr content x = 0.016 . However, for the films with x > 0.02, the aggregation of Cr atoms is strongly enhanced as both Ts and x increase, which not only brings strong compressive strain in the epilayer, but also roughens the surface. The origin of room-temperature ferromagnetism in (Ga, Cr)As films with nanoclusters is also discussed.
Keywords :
Curie temperature; III-V semiconductors; aggregation; annealing; chromium; compressive strength; ferromagnetic materials; gallium arsenide; magnetic thin films; semiconductor thin films; semimagnetic semiconductors; surface roughness; (GaCr)As; Curie temperature; compressive strain; diluted magnetic semiconductor; growth parameter dependence; magnetic films; magnetic properties; post-growth annealing; room-temperature ferromagnetism; structural characterizations; surface roughness; temperature 250 C; Magnetic analysis; magnetic semiconductors; molecular-beam epitaxial growth;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2008.2003046
