Study of the optical and thermoluminescent properties of Brazilian alexandrites

• Grant number: 20/15626-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2021
• Effective date (End): December 31, 2023
• Field of knowledge: Engineering - Mining Engineering - Mineral Prospecting
• Principal Investigator: Neilo Marcos Trindade
• Grantee: Alexia Oliveira Silva
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 23/04955-7 - Investigation of phototransferred thermoluminescence in Alexandrite pellets, BE.EP.IC

Abstract

Alexandrite (BeAl2O4: Cr3 +) is one of the varieties of chrysoberyl that is widely found in Brazil and has recently been studied to act as a dosimetric material because its composition combines BeO and Al2O3, oxides most used commercially as a dosimeter. As it is a mineral with potential for dosimetric use, it is important to have knowledge of the effects of ionizing radiation in the absorption and emission centers of the material, based on the use of optical absorption and thermoluminescence (TL) techniques. Preliminary studies with beta radiation have shown that alexandrite exhibits five TL peaks (heating rate 1ºC / s) ~ 80ºC (I), 130ºC (II), 170ºC (III), 260ºC (IV) and 310ºC (V), of which the last two peaks have dosimetric characteristics. From the TL emission curve, it is possible to obtain kinetic parameters, such as energy, frequency factor and kinetic order of the possible dosimetric peaks, which describe the luminescent characteristics of the material. In addition, to verify the influence of ionizing radiation on the optical properties of alexandrite, the effects of pre- and post-irradiation on the optical absorption bands, in the ultraviolet - visible region, will be investigated. The chemical composition of the samples will be obtained through microanalysis by scanning electron microscopy (SEM). The research will be carried out in collaboration with the University of São Paulo.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARTINS, R. T. E. K.; FERREIRA, I. A.; SILVA, A. O.; NUNES, M. C. S.; ULSEN, C.; KUNZEL, R.; SOUZA, M. M.; CHITHAMBO, M. L.; YOSHIMURA, E. M.; TRINDADE, N. M.. Thermoluminescence of rose quartz from Minas Gerais, Brazil. Radiation Physics and Chemistry, v. 209, p. 11-pg., 2023-04-15. (21/05042-0, 18/05982-0, 21/10117-9, 22/07200-4, 21/12758-1, 20/15626-6, 19/05915-3)