Diffraction Anomalous Fine-Structure Study Of Strained Ga1-Xinxas On Gaas(001)

Diffraction anomalous fine-structure measurements performed at both the Ga and As K edges have determined the Ga-As bond length to be 2.442+/-0.005 Angstrom in a buried, 213-Angstrom-thick Ga0.785In0.215As layer grown coherently on GaAs(001). This bond length corresponds to a strain-induced contraction of 0.013+/-0.005 Angstrom relative to the Ga-As bond length in bulk Ga1-xInxAs of the same composition. Together with recent extended x-ray-absorption fine-structure measurements performed at the In K edge [Woicik et al., Phys. Rev. Lett. 79, 5026 (1997)], excellent agreement is found with the uniform bond-length distortion model for strained-layer semiconductors on (001) substrates.