The structure of lead-indium phosphate and lead-scandium phosphate glasses

Lead-indium phosphate and lead-scandium phosphate glasses exhibit a number of useful properties Such as the efficient transmission of visible light, a high index of refraction, a low preparation temperature and low melt visco sity, and good chemical durability. The short-range and intermediate-range order structures of (PbO)(56.3)(In3O2)(4.2)(P2O5)(39.5) and a (PbO)(54.2)(S c3O2)(3.6)(P2O5)(42.2) glass were studied by time-of-flight neutron diffrac tion. From analyses of the measured structure factors of these glasses and those of a pure P2O5 glass and a (PbO)(58.8)(P2O3)(41.2) glass, both the br eakdown of the P2O5 network: structure to short PO4-chain-like units by the addition of metal oxides and the local environment of the dopant In and Sc ions were characterized. The In-O and Sc-O distance (2.1 Angstrom) is shor ter than that of Pb-O (2.52 Angstrom) and the coordination number for Sc-O (6.1) and In-O (5.5) is slightly higher than that of Pb-O (5.3).(C) 1999 El sevier Science B.V. All rights reserved.