Thermal and structural properties of magnesium tetraborate produced by solid state synthesis and precipitation for use in thermoluminescent dosimetry
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2019
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Radiation Physics and Chemistry
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Magnesium tetraborate is a phosphor with relevant characteristics for radiation dosimetry purposes. One of the
main challenges on this material is still the understanding of its structure and luminescent processes involved in
dosimetric performance. In this work, all the steps of the material production through DTA/TG, XRD and SEM
techniques were evaluated to understand the main physical and chemical changes during the thermal process
(calcination and sinterization) to produce the MgB4O7 samples. Two synthesis processes of MgB4O7 were studied:
precipitation (P.S) and solid state (S.S). Finally, the luminescence efficiency of the pellets was investigated
in function of different sintering temperatures. The initial stage of DTA/TG curves of the material just after the
mixing of starting materials, regardless the synthesis, is marked by endothermic events caused by dehydration,
decomposition of hydroxyl groups and hydrated borate phases. At higher temperatures, the curves are marked
by exothermic events related to crystalline transitions, but the peak obtained for the S.S is better defined in
comparison to P.S. Moreover, the DTA/TG analyses of the pellets prior and after the sinterization, showed that
the process is more relevant for the MgB4O7 pellets produced by S.S (950 °C), dramatically reducing its higroscopicity.
The SEM images reinforce the importance of the sintering process to create a resistant detector and
with a more homogenous and cohesive surface, therefore increasing it luminescence properties. The thermoluminescent
(TL) sensitivity of MgB4O7:Dy0,5% pellets produced via S.S, sintered at 950 °C, is 4 times higher
compared to the ones sintered at 950 °C, via P.S. The materials produced via P.S did not present relevant changes
in their TL sensitivity for sintering temperatures above 400 °C.
Como referenciar
SOUZA, LUIZA F. de; CALDAS, LINDA V.E.; JUNOT, DANILO O.; SILVA, ANDERSON M.B.; SOUZA, DIVANIZIA N. Thermal and structural properties of magnesium tetraborate produced by solid state synthesis and precipitation for use in thermoluminescent dosimetry. Radiation Physics and Chemistry, v. 164, p. 1-5, 2019. DOI: 10.1016/j.radphyschem.2019.108382. Disponível em: http://repositorio.ipen.br/handle/123456789/30487. Acesso em: 26 Apr 2024.
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.