Title
TL in green tourmaline: Study of the centers responsible for the TL emission by EPR analysis
Date Issued
01 January 2019
Access level
metadata only access
Resource Type
journal article
Author(s)
Universidad Federal de Sao Paulo
Universidad de Sao Paulo
Publisher(s)
Elsevier B.V.
Abstract
Electron paramagnetic resonance (EPR) studies have been carried out to identify the defect centers responsible for the thermoluminescence (TL) peaks in the mineral tourmaline. The mineral exhibits three TL peaks approximately at 170, 250 and 310 °C. The EPR spectrum of the green tourmaline sample pre-heated to 500 °C presented a large signal around g = 4.3 due to Fe3+ ion. Room temperature EPR spectrum of irradiated green tourmaline shows the formation of two defect centers in the region of g = 2.0. One of the centers (center II) with a g factor equal to 1.96 is identified as an F+-center and is related to the observed high temperature 250 and 310 °C TL peaks. Center I exhibiting a doublet is due to hydrogen atoms (H0), stable in the crystal lattice at room temperature and this center correlates with the TL peak at 170 °C of the green tourmaline. An optical absorption measurement also was carried out. Bands at around 430, 730 and 1100 nm have been observed.
Start page
324
End page
328
Volume
205
Language
English
OCDE Knowledge area
Física de partículas, Campos de la Física Electroquímica
Scopus EID
2-s2.0-85053827921
Source
Journal of Luminescence
ISSN of the container
00222313
Sponsor(s)
The authors wish to thank Ms. E. Somessari and Mr. C. Gaia, Instituto de Pesquisas Energeticas e Nucleares (IPEN), Brazil, for kindly carrying out the irradiation of the samples. This work was carried out with financial support from Fundação de Amparo à Pesquisa do Estado de São Paulo - FAPESP (Process number 2014/03085-0 ).
Sources of information: Directorio de Producción Científica Scopus