First attempt to identify site occupation preference coefficients of a quaternary alloy: The InAsxPySb1-x-y system

Abstract The characterization of quaternary alloys is a particularly complex task. However, EXAFS is a powerful method, suitable to obtain information about the local atomic structure of a sample and to analyze the ion distributions within any defined configuration. In the truly quaternary InAsPSb alloy we collected EXAFS spectra at different atomic edges and their Fourier Transform were analyzed using the multivariate Partial Least Square Regression method. The InAsPSb structure and its ion distributions within the twelve multinary configurations were determined together with site occupation preferences. The sphalerite structured InAsPSb alloy is characterized in the metastable range, by preferences with a significantly attenuated value, a condition that enhances the populations of its three symmetrical binary configurations. The attenuations, respect to Bernoulli distributions, for the metastable growth region and beyond this region were also evaluated for the first time.