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Photoluminescence (PL), PL lifetime, and radioluminescence (RL) measurements were made on LaF3 nanoparticles doped with Eu3+ or Sm3+. The radiative lifetimes decreased with increasing rare earth concentrations, which can be attributed to energy transfer to the surface of the nanoparticles followed by non-radiative recombination. The RL signal increases with increasing concentration for Eu3+ concentrations up to 20% Eu3+ but it saturates and disappears for >10% Sm3+. A dose-independent RL was observed up to 10 kGy during continual X-ray irradiation for Eu3+ and Sm3+ doped nanoparticles, which is advantageous for real time dosimetry applications (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A series of cerium-doped compounds with the composition Ba1-xLaxCl2+x and 0 < x < 0.5 have been prepared in ceramic form. We find from the powder X-ray diffraction patterns that the compounds adopt the cubic fluorite structure for 0.05 < x < 0.34. Samples with x ~ 0.2 are translucent. When doped with trivalent cerium, the materials show photoluminescence emission peaks at 350, 372 nm (for the Ba0.66La0.34Cl2.34 composition); the photoluminescence decay can be fitted with a single exponential with decay time 25 ns. The scintillation pulse height analysis shows a photopeak for 137Cs which can be used to compute a light yield of 4000 photons/MeV. The scintillation decay is non-exponential, with a rapid initial decay which can be represented approximately by a decay constant of ~100 ns, but there is a substantial delayed scintillation which extends over several microseconds. [ABSTRACT FROM AUTHOR]