Síntese e caracterização termoluminescente de cerâmicas de mgal2o4: ca sinterizadas a laser

Abstract

n this work, calcium-doped MgAl2O4 ceramics were laser-sintered and characterized aiming their application for thermoluminescent dosimetry. The powders were synthesized by the polymeric precursor method and calcined at 1000 °C/2h. For sintering, the calcined powders were conformed by uniaxial pressing (90 kgf) in cylindrical bodies, approximately 4 mm in diameter and 1.2 mm thick, and sintered using a CO2 laser as the main heating source. The sintered ceramic bodies showed a relative density from 91 to 95%, increasing as the Ca concentration increased. The samples were characterized by the X-Ray diffraction (XRD), scanning electron microscopy (SEM) and thermoluminescence (TL) techniques. The XRD results confirmed the formation of the single crystalline phase for all samples. The TL glow curve of the MgAl2O4 doped with 1 mol% Ca showed a single peak centered at 170 ⁰C with the signal varying linearly as a function of the radiation dose in the range from 0.2 - 5Gy and a 20% decay, 1000 min after ceased the excitation.