Lattice Parameter Measurement of GaAs Crystals Using Monochromatic Synchrotron Radiation

Abstract
A high-resolution diffractometer with a monolithic Si monochromator was developed for lattice parameter (d) measurements using synchrotron radiation. The accuracy attained was 5.9×10-6 in terms of Δ d/d. This degree of accuracy makes it possible to discuss the lattice parameter variation due to composition shifts in GaAs crystals. However, a preliminary study implied that thermally-induced elastic strain affects the lattice parameter more than the material composition shifts for crystals with the 104∼105 cm-2 order of dislocation density.