Structural and physical properties of As_xSe_100-x glasses

We prepare the samples of AsxSe100-x glasses with x = 20, 31, 40 and 50, and measure the glass-transition temperatures Tg, the density and elastic, and optical properties of the glasses. The density, elastic constants and third optical nonlinearity coefficient are found to exhibit the maximal values for the As40Se60 composition. Analysis of x-ray photoelectron spectra of these AsxSe100-x glasses indicate that the chemically stoichiometric As40Se60 consists of perfect corner-sharing pyramidal AsSe3/2 units, while the others contain defect bonds such as As - As and Se - Se. The optical nonlinearity does not correlate with the concentration of Se, contrary to the report by Quemard et al for Ge - Se glasses.