Abstract: | Thermoluminescence (TL), optical absorption (OA), electron spin resonance (ESR) and their relation to point defects in spessartine have been investigated. The TL glow curve presented four peaks at 150, 220, 260 and 335 °C. The 150 and 335 °C TL peaks growth curves presented a linear growth with radiation dose up to about 400 Gy, supralinearity above this dose, and saturation around 800–1000 Gy. The OA spectrum presented allowed spin transition bands due to Fe3+ and Mn2+ in dodecahedral environment. Absorption bands due to ultraviolet charge transfer of Fe3+ in octahedral and tetrahedral positions were also observed. Two ESR, a strong one around g?~?2 due to Fe3+ in octahedral position, and another weaker one at g?~?4 due to Fe3+ in tetrahedral position, have been detected. The effect of high temperature annealing (600–900 °C) before irradiation was also investigated. |