Extended x-ray-absorption fine-structure study ofGa1−xInxAsrandom solid solutions

Abstract

The extended x-ray-absorption fine structure was measured on the $K$ edges of each of the elements in ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{In}}_{x}\mathrm{As}$ solid solutions for $x$ ranging from 0 to 1. The Ga-As and In-As near-neighbor distances remain nearly constant across the solid solution, varying by only 0.04 \AA{}. The average cation-anion distance, on the other hand, changes by 0.174 \AA{}. The second-neighbor spectra indicate that the anion (As) sublattice is the more distorted, with two distributions of As-As distances, separated by 0.24 \AA{}. In contrast, the cation (Ga,In) sublattice approximates an average face-centered-cubic lattice, i.e., a virtual crystal, with cation-cation distributions which are peaked within 0.05 \AA{} of the mean. This type of first- and second-near-neighbor environment is similar to that in chalcopyrite with $\frac{c}{a}=2$ and $u=0.270$, rather than that of an average, or virtual, crystal.