DIFFRACTION ANOMALOUS FINE-STRUCTURE STUDY OF STRAINED GA1-XINXAS ON GAAS(001)

Diffraction anomalous fine-structure measurements performed at both th e 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 laye r grown coherently on GaAs(001). This bond length corresponds to a str ain-induced contraction of 0.013+/-0.005 Angstrom relative to the Ga-A s bond length in bulk Ga1-xInxAs of the same composition. Together wit h recent extended x-ray-absorption fine-structure measurements perform ed 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.