Thermoluminescence and defect centers in β-CaSiO₃ polycrystal

β: CaSiO₃ polycrystal was synthesized by the devitrification method. The polycrystal exhibits three thermoluminescence (TL) peaks at 124 °C, 250 °C and 306 °C. Electron paramagnetic resonance (EPR) spectroscopy was used to study the defect centers induced in the polycrystal by gamma irradiation and to identify the centers responsible for the TL process. Three defect centers contribute to the observed spectrum at room temperature. Center I with principal g-values 2.0135, 2.0094 and 2.0038 is attributed to O⁻ ion and the center appears to be the recombination center for 124 °C, 147 °C and 306 C TL peaks. Center II exhibiting an isotropic g-value of 2.00025 is identified as an F⁺-center (singly ionized oxygen vacancy). F⁺-center is also observed to be a recombination center for several TL peaks. Center III is assigned to a Ti³⁺ center displaying an orthorhombic g-tensor with principal values g₁ = 1.9830, g₂ = 1.9741 and g₃ = 1.9046. This center is associated with 124 °C and 147 °C TL peaks. TL emission spectrum of β-CaSiO₃ shows two emission bands at 370 and 520 nm.