Luminescence properties of Ce(3+)-doped NaPrP4O12 polyphosphate.

Studies on the crystal structure and luminescence properties have been performed for the NaPr(1-x)Ce(x)P(4)O(12) polyphosphate series. Excitation and emission spectra of Pr(3+) and Ce(3+) luminescence from NaPrP(4)O(12):Ce(3+) clearly reveal an efficient Pr(3+ ) → Ce(3+) energy transfer via migration over the Pr(3+)-sub-lattice and a nonradiative resonant transfer to the Ce(3+) ions. Analysis on scintillation characteristics of the NaPr(1-x)Ce(x)P(4)O(12) series shows a maximum light yield of 11,000 ± 1000 ph MeV(-1) for NaPr(0.99)Ce(0.01)P(4)O(12), proving the studied polyphosphates to be promising for application in the detection of x-ray and gamma quanta.

Crystal structure and luminescence properties of LiYP4O12:Ce3+ phosphor.

LiYP(4)O(12) polyphosphate doped with Ce(3+) ions was prepared by the melt solution technique. The crystal structure, interatomic distances, and atom coordination numbers were determined using x-ray powder diffraction. A study of the spectral-kinetic luminescent properties was performed employing excitation with pulsed radiation from a synchrotron (UV-VUV range) and a laboratory x-ray source. The characteristics of Ce(3+) luminescence, namely the emission doublet maxima at 3.97 and 3.72 eV and the 4f-5d excitation maxima at 4.20, 5.11, 5.40, 5.65 and 6.55 eV, are discussed in terms of crystal field splitting in a low-symmetry site of the LiYP(4)O(12) host lattice. The location of the Ce(3+) energy levels with respect to the valence and conduction bands of the LiYP(4)O(12) host is estimated from the temperature dependence of the decay time measured for Ce(3+) 5d-4f luminescence.

Luminescence properties of Ce(3+)-doped LiGdP(4)O(12) upon vacuum-ultraviolet and x-ray excitation.

Luminescent-kinetic studies for LiY(0.9)Ce(0.1)P(4)O(12), LiGd(0.9)Ce(0.1)P(4)O(12) and NaGd(0.9)Ce(0.1)P(4)O(12) phosphates which were prepared by the melt solution technique have been performed using synchrotron radiation excitation within 3-12.4 eV energy range and x-ray radiation at T = 10-300 K. The [Formula: see text] transfer at 10 K and bidirectional [Formula: see text] mechanisms of energy transfer at 300 K have been revealed based on the analysis of the excitation spectra and decay kinetic measurements of Ce(3+) luminescence. The participation of the Gd sublattice in the energy migration process to the Ce(3+) centers causes the appearance of a slow component in the decay kinetics of the x-ray-excited luminescence pulse. The luminescence efficiency of LiY(0.9)Ce(0.1)P(4)O(12), LiGd(0.9)Ce(0.1)P(4)O(12) and NaGd(0.9)Ce(0.1)P(4)O(12) upon x-ray excitation at room temperature is discussed.