EXAFS study of the local structure of InAs up to 80 GPa

The present paper concerns x-ray absorption spectroscopy experiments at the As K-edge on InAs up to 80 GPa. The aim of this study is to obtain quantitative information on the local environment of As in the post-NaCl phases of InAs. These measurements confirm the absence of the CsCl phase, and the analysis of the fine structure of the x-ray absorption allows us to characterize the local structure of the high pressure phases of InAs from their onset of appearance. While the Cmcm phase is locally very similar to the NaCl structure, having a first coordination shell of six indium atoms, above 31 GPa an increasing number of As atoms are detected within a distance of 3.16 angstrom.