Pulsed neutron diffraction from GeS2-based sulphide glasses

Pulsed neutron diffraction has been used to investigate the structure of st oichiometric 5(GeS2).(As2S3) glass. The high real-space resolution reveals chemical disorder in the form of homopolar bonds that cannot be clearly obs erved by any other direct structural probe. The sulphur-sulphur peak in the neutron correlation function is markedly less reliable than the cation-cat ion peak for quantifying the chemical disorder. For 5(GeS2).(As2S3) glass, the cation-cation coordination number, n(XX), is 0.24 and this implies a su lphur-sulphur coordination number, n(SS), of 0.13. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.