Effects of high-temperature annealing on ESR properties of solid solutions of garnet minerals

Author(s)

Rao, T. K. Gundu ^[1] ; Cano, Nib F. ^[2] ; Chubaci, Jose F. D. ^[1] ; Watanabe, S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Fis, Rua Matao, Travessa R 187, BR-05508090 Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Ciencias Mar, Santos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS; v. 91, p. 158-162, APR 2016.
• Web of Science Citations: 1

Abstract

A garnet (G7) silicate mineral belonging to pyralspite subgroup was studied using the technique of electron spin resonance (ESR). This study shows that iron is present in G7 as isolated species as well as species coupled by dipolar interactions. The ESR data shows a gradual increase of cluster of Fe3+ ions accompanied by decrease of dipolar interactions and increase of possible exchange interactions at high temperature. The Fe2+ -> Fe3+ oxidation process occurs in the garnets as a function of annealing temperature. Thermoluminescence (11) peaks at approximately 190 and 340 degrees C are observed in the irradiated G7 garnet. Investigations using the technique of ESR were carried out to identify the centers involved in the TL process. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/03085-0 - Quaternary geochronology of Southeastern and Southern coast of Brazil
• Grantee: Shigueo Watanabe
• Support Opportunities: Research Projects - Thematic Grants