Dosimetric and optical properties of CaSO4:Tm and CaSO4:Tm,Ag crystals produced by a slow evaporation route
| Autor: | Marcos V. dos S. Rezende, Ana G.M. Santos, Danilo O. Junot, Divanizia N. Souza, Linda V.E. Caldas, Patrícia L. Antonio |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Dopant Band gap Doping Biophysics Analytical chemistry chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Biochemistry Evaporation (deposition) Atomic and Molecular Physics and Optics Silver nanoparticle 0104 chemical sciences law.invention Crystal Thulium chemistry law 0210 nano-technology Light-emitting diode |
| Zdroj: | Journal of Luminescence. 210:58-65 |
| ISSN: | 0022-2313 |
| DOI: | 10.1016/j.jlumin.2019.02.005 |
| Popis: | The motivation of this work was to produce TL dosimeters based on crystals of CaSO4 doped with thulium and silver, by means of a suitable new route. The crystals were produced by an adaptation of the slow evaporation route using calcium carbonate (CaCO3) as precursor, and incorporating the dopants (Tm2O3 and silver nanoparticles) in a solution of sulfuric acid, which is evaporated resulting in CaSO4:Tm or CaSO4:Tm,Ag crystal powders. X-ray diffraction analyses showed that the produced samples exhibit only a single phase corresponding to the crystal structure of anhydrite. Optical characterization was performed to determine the band gap of the materials. Samples did not show a reasonable OSL signal after stimulation with blue LEDs. TL characteristics such as glow curves, linearity and reproducibility of response, minimum detectable dose and fading were evaluated. The CaSO4:Tm samples showed TL emission glow curves with peaks in temperatures proper for dosimetry. The CaSO4:Tm,Ag samples presented a very intense peak displaced to high temperatures that could only be observed by applying heating rates below 4 °C/s. Samples doped with thulium oxide and silver nanoparticles showed the highest TL intensity and lowest fading. |
| Databáze: | OpenAIRE |
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