Correlated PL, TL and EPR study in γ-rays and C6+ ion beam irradiated CaMg2(SO4)3:Dy3+ triple sulphate phosphor

Abstract

CaMg2(SO4)3 host and CaMg2(SO4)3:Dy3+ phosphor (where Dy3+ = 0.05, 0.1,0.2, 0.5 and 1 mol%) were synthesized via solid state synthesis method at 700 °C. Phase formation of the compound was confirmed by obtaining its X-ray diffraction (XRD) pattern and the surface morphology was analyzed with the scanning electron microscopy (SEM) technique. Photoluminescence (PL) excitation and emission spectra of CaMg2(SO4)3:Dy3+ phosphor shows characteristic emission and excitation peaks of Dy3+ ions, which confirms the doping of Dy3+ ions in the host. Material was irradiated with γ-rays and C6+ ion beam. Thermoluminescence (TL) glow curve of irradiated material was recorded at the heating rate of 5 °C s−1. A single TL peak is obtained after γ-rays irradiation for CaMg2(SO4)3 host at 158 °C and two TL peaks were seen for CaMg2(SO4)3:Dy3+ at 129 °C and 355 °C. With increase in Dy3+ concentration, TL intensity is increased but the nature of TL glow curve remained same. Material was quenched from 400 °C and its TL was recorded by irradiating it with γ-rays and C6+ ion beam (75 MeV). TL intensity of quenched CaMg2(SO4)3:Dy3+ compound enhanced significantly as compared to annealed CaMg2(SO4)3:Dy3+ compound. Electron paramagnetic resonance (EPR) study was carried out on irradiated (γ-ray and C6+ beam) CaMg2(SO4)3:Dy3+ compound to analyse radicles formed in the irradiation process and possible mechanism of TL. Correlated study of TL, PL and EPR is done.