Thermally reversible gamma-ray-induced redox reaction between substitutional iron and aluminum impurity centers in a silica glass
IR@CGCRI: CSIR-Central Glass and Ceramic Research Institute, Kolkata
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| Title |
Thermally reversible gamma-ray-induced redox reaction between substitutional iron and aluminum impurity centers in a silica glass
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| Creator |
Debnath, Radhaballabh
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| Subject |
Glass
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| Description |
The magnetic properties of the substitutional iron and aluminum impurity centers in a sintered Vycor silica glass were studied before and after 1.1-1.3 MeV gamma irradiation. Observation of two overlapping spin resonances (g similar to 4.20-4.28) in the spectra of both the irradiated and preirradiated glasses indicated the existence of two types of tetra coordinated substitutional iron centers of the [FeO(4)(-)/Na(+)](0) type. The intensity of these electron-paramagnetic resonance (EPR) signals decreased upon gamma irradiation of the glass with concomitant generation of aluminum hole center [AlO(4)](0), which was manifested by the occurrence of a new six-line EPR signal with g = 2.009, while thermal annealing of these aluminum oxygen hole centers restores the intensity of the iron centers almost to their preirradiation level. This result suggests that if not the whole, a major fraction of the electrons released in the process of gamma -ray-induced hole trapping at the Al site are captured by the substitutional iron centers. The electron traps, thus formed, are quite stable and can be deactivated by thermal stimulation.
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| Publisher |
Materials Research Society
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| Date |
2001
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cgcri.csircentral.net/1398/1/debnath2001.pdf
Debnath, Radhaballabh (2001) Thermally reversible gamma-ray-induced redox reaction between substitutional iron and aluminum impurity centers in a silica glass. Journal of Materials Research, 16 (1). pp. 127-131. ISSN 0884-2914 |
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| Relation |
http://cgcri.csircentral.net/1398/
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