Production and characterization of spodumene dosimetric pellets by prepared by pechini and proteic sol-gel route

Spodumene is an aluminosilicate that has proven suitable for high-dose TL dosimetry of beta or gamma rays. Due to the presence of lithium in its chemical composition (LiAlSi2O6 - β-LAS), it has potential as neutron dosimeter as well. This silicate may be obtained naturally or synthetically. The synthetic LAS has been produced by solid state reaction and conventional sol-gel, whose difficulty arises from the need to employ high temperatures and high cost reagents, respectively. Alternative routes like Pechini and proteic sol-gel methods are promising, because they can reduce production costs and the possibility of environmental pollution. This work aimed at producing spodumene with the proteic sol-gel method using edible unflavored gelatin as a precursor and also with the Pechini method. The products were characterized physically and morphologically, and their applicability as TL dosimeter was investigated, comparing the sensitivity of samples produced by different methods. Two sets of samples were produced using different sources of silicon, tetraethyl orthosilicate (TEOS, Si(C2H5O)4) and silica (SiO2). The materials produced were characterized by X-ray diffraction and by thermal analysis in order to evaluate their structural properties, as well as possible temperature-dependent changes in physical or chemical properties. The syntherized pellets produced with these crystals were irradiated with a 90Sr-90Y source and their TL glow curves were evaluated. The production of β-LAS was successful by both methods, either using silica or TEOS as a silicon source. The crystals were obtained using much lower temperatures than by methods described in literature. We observed that the method of powder production was critical to develop a radiation detector: the best TL material was the powder produced using silica and the Pechini Method.