High Real-Space Resolution Measurement of the Local Structure of Ga_1-xIn_xAs Using X-Ray Diffraction

High real-space resolution atomic pair distribution functions PDFs from the alloy series Ga_1-xln_xAs have been obtained using high-energy x-ray diffraction. The first peak in the PDF is resolved as a doublet due to the presence of two nearest neighbor bond lengths, Ga-As and In-As, as previously observed using x-ray absorption fine structure. The widths of nearest, and higher, neighbor PDF peaks are analyzed by separating the broadening due to static atom displacements from the thermal motion. The PDF peak width is 5 times larger for distant atomic neighbors than for nearest neighbors. The results are in agreement with model calculations.