Ca2Al2SiO7:Ce3+ phosphors for mechanoluminescence dosimetry

A series of Ce3+ ion single-doped Ca2Al2SiO7 phosphors was synthesized by a combustion-assisted method at an initiating temperature of 600 degrees C. The samples were annealed at 1100 degrees C for 3 h and their X-ray diffraction patterns confirmed a tetragonal structure. The phase structure, particle size, surface morphology and elemental analysis were analyzed using X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy techniques. Thermoluminescence (TL) intensity increased with increase in ultraviolet (UV) light exposure time up to 15 min. With further increase in the UV irradiation time the TL intensity decreases. The increase in TL intensity indicates that trap concentration increased with UV exposure time. A broad peak at 121 degrees C suggested the existence of a trapping level. The peak of mechanoluminescence (ML) intensity versus time curve increased linearly with increasing impact velocity of the moving piston. Mechanoluminescence intensity increased with increase in UV irradiation time up to 15 min. Under UV-irradiation excitation, the TL and ML emission spectra of Ca2Al2SiO7:Ce3+ phosphor showed the characteristic emission of Ce3+ peaking at 400 nm (UV-violet) and originating from the Ce3+ transitions of 5d-4f (F-2(5/2) and F-2(7/2)). The photoluminescence (PL) emission spectra for Ca2Al2SiO7:Ce3+ were similar to the ML/TL emission spectra. The mechanism of ML excitation and the suitability of the Ca2Al2SiO7:Ce3+ phosphor for radiation dosimetry are discussed. Copyright (C) 2016 John Wiley & Sons, Ltd.