Luminescence and defect centres in MgSrAl10O17:Sm3+ phosphor

An efficient reddish orange emission MgSrAl10O17:Sm3+ phosphor was prepared by the combustion method. The phosphor has been characterized by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis measurements. Photoluminescence spectrum revealed that samarium ions are present in trivalent oxidation states. The phosphor exhibits two thermally stimulated luminescence (TSL) peaks at 210 °C and 450 °C. Electron spin resonance studies were carried out to identify the defect centres responsible for the TSL process in MgSrAl10O17:Sm3+ phosphor. Three defect centres have been identified in irradiated phosphor and these centres are tentatively assigned to an O− ion and F+ centres. O− ion (hole centre) correlates with the 210 °C TSL peak while one of the F+ centres (electron centre) appears to relate to the 450 °C TSL peak.