Solid state 77Se NMR investigations on arsenic-selenium glasses and crystals

Some resolved solid state Se-77 NMR spectra are presented in the AsxSe1-x glass family at ambient temperature. They exhibit three different kinds of Se environments. A comparison with the parent crystalline phases permits to assign the lines to Se-Se-Se, Se-Se-As and As-Se-As Se atom neighborhoods. The measurements of the relative intensities of the lines prove the validity of the intermediate range order structural model known as,the "chains crossing model" which is based on AsSe3 pyramids homogeneously distributed among the divalent Se atoms network. In particular, any scenario involving a selenium clustering process is refuted. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.