Atomic-Resolution Study of Lattice Distortion of a Buried InGa1-xAs Monolayers in GaAs(001)

Published

November 1, 1999

Author(s)

T L. Lee, M Pillai, Joseph Woicik, G Labanda, P Lyman, S A. Barnett, Michael Bedzyk

Abstract

X-ray standing wave measurements were used to study the strain in one monolayer of pseudobinary alloy InxGa1-xAs buried in GaAs(001). The measured In position along the [001] direction, which exhibits a linear dependence on the In concentration x, supports the validity of macroscopic continuum elasticity theory at the one monolayer limit. A random-cluster calculation using a valence force field was performed to explain the origin of the vertical expansion of the strained layer observed by the experiment. With a cluster constructed for a buried monolayer of InxGa1-xAs in GaAs(001), the calculated As-In-As bond angle and the positions of the first nearest neighbor As atoms of In suggest that the linear dependence of the In height on the In concentration x is a combined result of the As-In-As bond bending and the local lattice relaxation at the GaAs/InxGa1-xAs interfaces. The calculated In-As and Ga-As bond lengths were found to depend weakly on the In concentration, consistent with an earlier calculation for the case of a thick InxGa1-xAs film on GaAs(001).

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

60

Issue

No. 19

Pub Type

Journals

Keywords

monolayer of GaAs/In_xGa_1-xAs, random-cluster calculation, x-ray standing wave (XSW)

Citation

Lee, T. , Pillai, M. , Woicik, J. , Labanda, G. , Lyman, P. , Barnett, S. and Bedzyk, M. (1999), Atomic-Resolution Study of Lattice Distortion of a Buried InGa_1-xAs Monolayers in GaAs(001), Physical Review B (Condensed Matter and Materials Physics) (Accessed April 24, 2024)