Structure of a Potassium Germanophosphate Glass by X-ray and Neutron Diffraction
Abstract
An increase of the Ge-O coordination numbers in binary germanate glasses with change of the K2O or P2O5 content, respectively, was previously found by diffraction experiments. The present work is aimed at clarifying the concomitant effect of both oxides. X-ray and neutron diffraction of high resolving power was used to characterize the ternary glass of nominal composition (K2O)0.125-(P2O5).0.375-(GeO2)0.50. Gaussian fitting of the P-O and Ge-O nearest-neighbour peaks in the correlation functions results in coordination numbers of 3.8±0.2 and 5.1±0.2, respectively, with distances of 0.153±0.001 or 0.183±0.002 nm, respectively. These parameters are consistent with a network formed of PO4 and GeOn polyhedra with n=4,5, or 6 where Ge-O-P bridges dominate. The K+ ions coordinate terminal oxygens of the PO4 units. The first diffraction peak appears at a small value of ~ 7 nm-1 that deviates considerably from that of other oxide glasses.
Recommended Citation
U. Hoppe et al., "Structure of a Potassium Germanophosphate Glass by X-ray and Neutron Diffraction," Solid State Communications, vol. 143, no. 8 - 9, pp. 403 - 407, Elsevier, Aug 2007.
The definitive version is available at https://doi.org/10.1016/j.ssc.2007.06.013
Department(s)
Materials Science and Engineering
Sponsor(s)
German Research Association
National Science Foundation (U.S.)
Keywords and Phrases
X-Ray Scattering; Disordered Systems; Neutron Scattering
International Standard Serial Number (ISSN)
0038-1098
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2007 Elsevier, All rights reserved.
Publication Date
01 Aug 2007
Comments
The work is supported by the Deutsche Forschungsgemeinschaft (contract KR 1372/9-2, Rostock University) and by the National Science Foundation (DMR 0305202, University of Missouri-Rolla).