Abstract
We report on the electrical conductivity of barium iron phosphate glass, a candidate for radioactive waste encapsulating glass. The glass composition has been optimized for slow dissolution in hot water because the precipitation of a stable hydration layer of FeO(OH) on the glass surface enhances the water durability of the glass. The mechanism of electrical conductivity of the glass is assumed to be an electron hopping between the electronic energy levels of Fe (II) and Fe (III) ions, obeying the electron carrier generation of Fe (II) → Fe (III) + e−. The electrical conductivity of the base glass was ∼3.2 x 10−7 to ∼5.0 x 10−4 S/cm, from 200 to 550°C, whereas samples with surface hydration layers after the water durability tests had conductivities one order of magnitude lower than the base glass sample. The electrical conductivity of a crystallized sample was ∼0.8 x 10−7 S/cm at 400°C. X-ray photoelectron spectroscopy revealed the existence of Fe (II) and Fe (III), and P−O−Fe (Ba) and P−O−P bonds, and it was found that electrical conductivity increased in the order of increasing Fe (II)/Fe (III) ratio for the bulk, the corroded, and the crystallized samples.
Recommended Citation
K. Mitsui et al., "Degradation Of Radioactive Waste Encapsulation Of BaO−FeOx−P2O5 Glass Evaluated From Electrical Conductivity," Journal of the American Ceramic Society, Wiley, Jan 2025.
The definitive version is available at https://doi.org/10.1111/jace.20434
Department(s)
Materials Science and Engineering
Publication Status
Full Access
Keywords and Phrases
electrical conductivity; glass; phosphates
International Standard Serial Number (ISSN)
1551-2916; 0002-7820
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Wiley, All rights reserved.
Publication Date
01 Jan 2025
Comments
Murata Science and Education Foundation, Grant JPMJSP2162