Radioluminescence properties of Ce3+-activated MGd(PO3)4 (MÂ =Â Li, Na, K, Cs)

Rare-earth phosphates MGd(PO3)4:1.0 mol% Ce3+ (M = Li, Na, K, Cs) powder samples were prepared by a solid-state reaction technique at high temperature. The radioluminescence spectra and light-yield characteristic of MGd(PO3)4:Ce3+ under X-ray irradiation were determined. It was found that, from LiGd(PO3)4:Ce3+ to CsGd(PO3)4:Ce3+, with the increasing of M+ radius, the doublet emission energy of Ce3+ ions decrease gradually but the light-yield increase significantly. Especially, CsGd(PO3)4:1.0 mol% Ce3+ has the highest X-ray excited light-yield of 24,400 photons/MeV with maximal emission peaks at 337 nm and 358 nm at room temperature. Due to its suitable emission wavelength range, high light-yield, high chemical stability and fast luminescence decay of Ce3+ emission, CsGd(PO3)4:Ce3+ may be a promising scintillation material.