Achieving high Curie temperature in (Ga,Mn)As.

Authors :: Wang, M.
Campion, R. P.
Rushforth, A. W.
Edmonds, K. W.
Foxon, C. T.
Gallagher, B. L.
Source :: Applied Physics Letters; 9/29/2008, Vol. 93 Issue 13, p132103, 3p, 3 Graphs
Publication Year :: 2008
Abstract: We study the effects of growth temperature, Ga:As ratio, and postgrowth annealing procedure on the Curie temperature T<subscript>C</subscript> of (Ga,Mn)As layers grown by molecular beam epitaxy. We achieve the highest T<subscript>C</subscript> values for growth temperatures very close to the two-dimensional–three-dimensional phase boundary. The increase in T<subscript>C</subscript>, due to the removal of interstitial Mn by postgrowth annealing, is counteracted by a second process, which reduces T<subscript>C</subscript> and which is more effective at higher annealing temperatures. Our results show that it is necessary to optimize the growth parameters and postgrowth annealing procedure to obtain the highest T<subscript>C</subscript>. [ABSTRACT FROM AUTHOR]