TL-OSL-EPR correlation studies of CaSiO3:Ce3+ phosphor synthesized by sol-gel

Callo-Escobar D.J.; Vilca Z.V.; Ayala Arenas J.S.; Mosqueira-Yauri J.; Benavente J.F.; Gundu Rao T.K.; Cano N.F. · Ceramics International (2026) · DOI: 10.1016/j.ceramint.2026.06.396

Resumen

Ce3+-activated calcium silicate (CaSiO3) phosphor, with a monoclinic crystal structure, was successfully synthesized through the sol-gel method to investigate the defect centers responsible for its luminescent properties. The thermoluminescence (TL), optically stimulated luminescence (OSL), and electron paramagnetic resonance (EPR) characteristics of the phosphor were exhaustively investigated after irradiation. The TL/OSL intensity of a sample doped with 0.05 mol% Ce was found to have the highest TL/OSL response among the other doped samples. Deconvolution of the TL and OSL curves revealed five first-order TL peaks and three components with distinct photoionization cross sections. The same traps were found to be responsible for both TL and OSL in this phosphor. EPR studies have been conducted to identify the defect centers formed due to γ-irradiation and to determine the centers associated with the luminescence process in the phosphor. The spectrum observed at room temperature has contributions from four defect centers. One of the centers (center I) is attributed to an O2− ion and is characterized by an axial g-tensor with principal values g∥ = 2.0096 and g⊥ = 2.0078. Center II with an isotropic g-value of 1.9995 is identified as an F+ center (singly ionized oxygen vacancy). Centers III and IV are characterized by an axial g-tensor and are ascribed to the F+ center.

Instituciones: Universidad Nacional de San Agustín de Arequipa