STRUCTURE OF ZINC HALIDE-BASED GLASSES

Raman spectroscopic studies on the multicomponent zinc halide-based glasses are summarized and X-ray absorption spectra of the glasses are measured along with zinc halide crystals in order to investigate the structure of the glasses and to obtain the structural parameters. Raman spectra are well explained by a structural model in which the glasses have two types of halides ions, i.e., bridging and non-bridging halide ions, and the glass network is composed of corner-sharing ZnX4 tetrahedra. The X-ray absorption spectra have been analyzed by means of a curve-fitting method using theoretical backscattering amplitudes and phase shifts. Bond distances between zinc and halide ions are shorter than those of the corresponding ZnX2 crystals by 0.01 to 0.02 angstrom. Coordination numbers of the glasses are smaller than those expected from Raman spectroscopy.