Thermoluminescence, fluorescence and electron paramagnetic resonance of natural alexandrite
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2023
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BRAZIL MRS MEETING, 21st
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Recent studies have proposed the investigation of alexandrite mineral (BeAl2O4:Cr3+) as a
potential luminescent dosimeter. Despite this, in-depth studies of defects and luminescent
centers in alexandrite were not investigated. It is proposed to characterize the
thermoluminescence (TL) emission spectra, fluorescence (FL) and electron paramagnetic
resonance (EPR) of alexandrite. TL dosimeters, when stimulated by thermal energy, emit
light proportional to the dose of ionizing radiation previously absorbed. The emitted
wavelength can be measured through thermoluminescence emission spectra. On the other
hand, EPR and FL provides additional information about mineral structure, enabling the study
of the effects of ionizing radiation on the sample. For TL, the samples were irradiated with Xrays
and measured by Lumi22 homemade system. EPR measurements were carried out using
a Bruker EMXplus spectrometer operating in the X-band at room temperature, 2 mW
microwave power, 100 kHz modulation frequency and 0.25 mT modulation amplitude. The
FL spectra were measured using the Duetta spectrofluorometer, with a 75 W xenon arc lamp
included. The data was collected by scanning excitation wavelengths in 360-480 nm and
recording emission in the wavelength range of 670-740 nm. Preliminary results indicate that
the TL emission spectra presented two peaks, at ~80°C and ~175°C, with emission centered
between 600 nm – 700 nm, related to Fe3+ and Cr3+, also detected by EPR. The FL spectra
showed two signals: an emission centered at 680 nm (Cr3+ in inversion center), and at 700
nm (Cr3+ in mirror symmetry). The results of all techniques used in this work suggest that
emissions are correlated to Cr3+ and Fe3+ ions.
Como referenciar
SILVA, ALEXIA O.; NUNES, MATHEUS C. dos S.; YOSHIMURA, ELISABETH M.; RODRIGUES JUNIOR, ORLANDO; TRINDADE, NEILO M. Thermoluminescence, fluorescence and electron paramagnetic resonance of natural alexandrite. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1016-1016. Disponível em: http://repositorio.ipen.br/handle/123456789/34562. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.