| Description |
ix, 102 leaves : illustrations ; 29 cm |
| Summary |
"A series of cesium phosphate glasses, XCs₂O·(1 - X)P₂O₅, where X <̲ 0.60 were prepared. The addition of ~16 mole% Cs₂O to P₂O₅ decreases the glass transition temperature (T[subscript g]) by 156K. T[subscript g] increases by 25K with the further addition of cesium oxide up to 60 mole% Cs₂O. The density of V-P₂O₅ is 2.39 g/cm³, and with cesium oxide additions the cesium phosphate glass density increases monotonically to 3.88 g/cm³ (59.1 mole% Cs₂O). The ³¹P magic angle spinning nuclear magnetic resonance (MAS NMR) spectra show that the addition of Cs₂O causes a continuous conversion of the 3D ultraphosphate network to the chain metaphosphate structure. There is a break in the Q² isotropic chemical shift ([delta][subscript iso]) at ~35 mole% Cs₂O. The ¹³³Cs MAS NMR spectra show a 90 ppm increase in [delta][subscript iso], which indicates a decrease in the average electron density around the cesium, more covalent Cs-O bonding, and a shorter average Cs-O bond length. The Raman data indicates a conversion of the 3D phosphate glass network to a chain metaphosphate glass structure with the addition of Cs₂O. The properties and spectroscopic results are interpreted using a structural model that considers the effects of composition on the average coordination environments of cesium ions"--Abstract, leaf 2. |
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