Calculation of Bond Lengths in Si1-xGex Alloys Based on the Valence-Force-Field Model

Abstract
Bond lengths in crystalline Si1-x Ge x alloys are calculated by the valence-force-field model. A zincblende like unit cell is used to simulate the structure of random alloys. The calculated length change normalized to the change predicted by the virtual-crystal approximation is about 0.35. The calculated bond lengths are compared with the experimental results obtained by EXAFS measurements.