Local structure in Ga1xInxSe alloys

In this work we study the local structure of layered Ga1 x In x Se alloys by means of X-ray Absorption. We complement our research with a Raman study. The available alloys have compositions close to the host binaries. The dependence of XANES (X-ray Near Edge Structure) features with synchrotron polarization clearly establishes the substitutional character of the alloying cations. Interstitial atoms, if present, remain under the detection limit of the technique. EXAFS (Extended X-ray Absorption Fine Structure) demonstrates the existence of Ga In bonds in the alloys. The cation-anion bond-lengths in the alloys remain similar to that of the pure compounds. There is no significant increase of the static disorder. The basic features of Raman spectra are those of the pure compounds, with the Raman peaks shifting continuously as the impurity cation is introduced. New features associated to defects are discussed.