Color Bleaching and Oxygen Diffusion in a Niobium Phosphate Glass

Author

L. Ghussn
R. M. C. V. Reis
Richard K. Brow, Missouri University of Science and TechnologyFollow
D. B. Baker

Abstract

The color of niobium phosphate glasses ranges from clear to deep blue depending on their thermal history. In this study, a glass with the nominal composition (mole %) 23K₂O·40Nb₂O₅·37P₂O₅ was treated in oxidizing and reducing atmospheres at temperatures around T^g (730 °C) and the color at room temperature was analyzed using optical spectroscopy. Electron spin resonance (ESR) spectroscopy shows that the blue color is associated with the presence of Nb⁴⁺ ions, which oxidize to Nb⁵⁺ in the clear glasses. Bleaching kinetics were determined from a series of heat treatments below T^g in flowing oxygen, and analyzed with an diffusion model that indicated an activation energy of 150 ± 31 kJ/mol.

Recommended Citation

L. Ghussn et al., "Color Bleaching and Oxygen Diffusion in a Niobium Phosphate Glass," Journal of Non-Crystalline Solids, vol. 401, pp. 96 - 100, Elsevier B.V., Oct 2014.

The definitive version is available at https://doi.org/10.1016/j.jnoncrysol.2013.11.004

Department(s)

Materials Science and Engineering

Keywords and Phrases

Color; Diffusion; ESR; Niobium; Phosphate

International Standard Serial Number (ISSN)

0022-3093

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2014 Elsevier B.V., All rights reserved.

Publication Date

01 Oct 2014