The structure of magnesium phosphate glasses

The structures of (MgO)(x)(P2O5)(100-x) glasses, with x = 40, 50, 60, have been studied by neutron diffraction. For all glasses the Mg-O coordination number NMg-O is around 6, Although no abrupt change in NMg-O around the metaphosphate composition (x = 50) was observed, the mean value and distribution of Mg-O distances changed with increases in the MgO content from 50 to 60 mol% and 40 to 50 mol%, respectively. The quasi-periodicity of the intermediate-range order contracts with an increase in MgO content from 50 to 60 mol%, These changes may represent the structural origin of the phosphate glass anomaly, (C) 1999 Elsevier Science Ltd, All rights reserved.