Sb incorporation at GaAs(001)-(2 x 4) surfaces

We examine the Sb incorporation and resulting surface reconstructions of Sb and GaSb deposited on GaAs(0 0 1). These films exhibit a mixed surface reconstruction of alpha 2(2 x 4) and alpha(4 x 3). Initially, Sb reacts with Ga On the Surface to form 2D islands of GaSb with an alpha(4 x 3) surface reconstruction. The 2D islands grow to a critical size of 30 nm(2), beyond which the atomic surface structure of the 2D island transforms to a alpha 2(2 x 4) reconstruction in order to reduce the strain induced surface energy. This transformation is limited by the availability of Ga, which is necessary in higher quantities for the a2(2 x 4) reconstruction than for the alpha(4 x 3). The transformation results in a mixed alpha(2 x 4)-alpha(4 x 3) surface where the surface reconstruction is Coupled to the surface morphology, which may in the future provide a pathway for self-assembly of structures. (C) 2008 Elsevier B.V. All rights reserved.