Structural inhomogeneities in fast ion conducting glasses - art. no. 134201

The structures of the ion conducting glasses LiCl-L2O-2B(2)O(3), (AgI)(0.6) -(Ag2O-B2O3)(0.4), CsI-4AgPO(3), and PbI2-9AgPO(3) have been investigated u sing 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 An gstrom. The (AgI)(0.6)-(Ag2O-B2O3)(0.4) glass shows exceptionally high scat tering intensity at low Q values (<0.5 <Angstrom>(-1)) due to the existence of chemical inhomogeneities on length scales up to at least 50 Angstrom. B oth the salt ions and the network atoms are inhomogeneously distributed, Th e first diffraction peak, located at 0.46 Angstrom (-1) in the total struct ure factor, is caused by a characteristic distance between B-O segments sep arated by salt ions. The LiCl-Li2O-2B(2)O(3) glass shows inhomogeneities on ly in the distribution of salt ions, where particularly the chlorine ions a re very inhomogeneously distributed. The ion concentration fluctuations occ ur on a wide range of length scales. In contrast to the investigated borate glasses, the two phosphate glasses show only minor structural inhomogeneit ies on length scales above 10 Angstrom.