EXTENDED X-RAY ABSORPTION FINE-STRUCTURE STUDIES OF SHORT-RANGE ORDER IN AMORPHOUS ZN-P FILMS

Amorphous Zn-P films containing 47 and 68 at.% P, prepared by vacuum evaporation, have been studied using Zn K-edge extended X-ray absorption fine structure (EXAFS). A least-squares fitting procedure and difference method have been applied to analyse the measured spectra. The results indicate that for the Zn53P47 film, a Zn-Zn contribution is involved in the near-neighbour tetrahedral coordination sphere. As the P content is increased, the number of Zn-Zn bonds is reduced to zero within the precision of the method. The relationship between the short-range order in the investigated films and the local atomic arrangements in corresponding crystalline polymorphs is discussed. Near-neighbour structural parameters deduced from EXAFS and large-angle X-ray scattering are also compared.