"Degradation Of Radioactive Waste Encapsulation Of BaO−FeOx−P2O5 Glass " by Kazuki Mitsui, Nobuyasu Nishioka et al.
 

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.

Department(s)

Materials Science and Engineering

Publication Status

Full Access

Comments

Murata Science and Education Foundation, Grant JPMJSP2162

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

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