Study of the centers responsible for the TL emission by EPR and PL analysis of Eu-doped CaSiO3 phosphors synthesized by the devitrification method

Gonzales-Lorenzo C.D.; Gundu Rao T.K.; Ccollque-Quispe A.A.; Ayala-Arenas J.; Gomes M.B.; Silva-Carrera B.N.; Gennari R.F.; Pachas V.S.; Monzon-Macedo F.; Loro H.; Chubaci J.F.D.; Cano N.F.; Rocca R.R.; Watanabe S. · Materials Research Bulletin (2024) · DOI: 10.1016/j.materresbull.2023.112607

Resumen

CaSiO3 doped at different ppm of Eu were synthesized by the devitrification method. Polycrystals exhibit a prominent high-temperature TL peak that increases in intensity and shifts toward higher temperatures with increasing amounts of dopant. TL emission spectrum of CaSiO3: Eu displays two very broad bands centered at 400 and 440 nm corresponding to the temperatures of 229.5 and 373.5 °C, respectively. PL measurements indicate the presence of Eu2+ and Eu3+ ions. EPR spectrum arises from two defect centers. One of the centers with principal g-values 2.016, 2.0091, and 2.0051 is attributed to O− ion and the center correlates with the TL peak at 236 °C. Center II with an isotropic g-value of 2.0018 is attributed to an F+ center and the center relates to the TL peak at 120 °C. Center III is also tentatively identified as the F+ center which is associated with the TL peak at 365 °C.

Instituciones: Universidad Nacional de San Agustín de Arequipa; Universidad Nacional de Ingeniería