Anharmonicity in GaAs0.065P0.935

Abstract

Inclusion of dispersion corrections in the generalized structure factor expression for the zinc blende structure give rise to the breakdown of Friedel's law for all even index reflections, an effect due to the presence of anharmonicity. Accurate X-ray diffraction intensity measurements have been obtained using a spherical single crystal of GaAs0.065P0.935 at 298 K. Least-squares refinement yield the Debye-Waller factors, BGa = 0.52 ± 0.01 Å2 and BAs/P = 0.39 ± 0.02 Å2, also the individual anharmonic thermal parameter βGa = −1.8 ± 1.3 × 10−17 J Å−3 and βAs/P = −0.8 ± 0.6 × 10−17 J Å−3. The residual index for the discrepancy between measured and calculated structure factors in the present work is R = 0.0172. The Bijvoet inequality between inverse reflections, reveals good agreement with the calculated values for a large number of reflections.