The structures of the ion conducting glasses ${\mathrm{L}\mathrm{i}\mathrm{C}\mathrm{l}-\mathrm{L}\mathrm{i}}_2{\mathrm{O}-2\mathrm{B}}_2{\mathrm{O}}_3,$ $({\mathrm{A}\mathrm{g}\mathrm{I})}_{0.6}{-(\mathrm{A}\mathrm{g}}_2{\mathrm{O}-\mathrm{B}}_2{\mathrm{O}}_3{)}_{0.4},$ ${\mathrm{C}\mathrm{s}\mathrm{I}-4\mathrm{AgPO}}_3,$ and ${\mathrm{PbI}}_2{-9\mathrm{AgPO}}_3$ have been investigated using small- and wide-angle neutron diffraction experiments. We have applied the reverse Monte Carlo modeling method to the experimental data with the aim to reveal the intermediate-range structure on a length scale of 5–50 Å. The $({\mathrm{A}\mathrm{g}\mathrm{I})}_{0.6}{-(\mathrm{A}\mathrm{g}}_2{\mathrm{O}-\mathrm{B}}_2{\mathrm{O}}_3{)}_{0.4}$ glass shows exceptionally high scattering intensity at low Q values (<0.5 ${\mathrm{\AA }}^{\mathrm{-}1}$) due to the existence of chemical inhomogeneities on length scales up to at least 50 Å. Both the salt ions and the network atoms are inhomogeneously distributed. The first diffraction peak, located at 0.46 ${\mathrm{\AA }}^{\mathrm{-}1}$ in the total structure factor, is caused by a characteristic distance between B-O segments separated by salt ions. The ${\mathrm{L}\mathrm{i}\mathrm{C}\mathrm{l}-\mathrm{L}\mathrm{i}}_2{\mathrm{O}-2\mathrm{B}}_2{\mathrm{O}}_3$ glass shows inhomogeneities only in the distribution of salt ions, where particularly the chlorine ions are very inhomogeneously distributed. The ion concentration fluctuations occur on a wide range of length scales. In contrast to the investigated borate glasses, the two phosphate glasses show only minor structural inhomogeneities on length scales above 10 Å.

• Received 19 March 2001

DOI:https://doi.org/10.1103/PhysRevB.64.134201