Steady‐state emission and excitation spectra and luminescence decay kinetics were studied at 80–300 K under excitation in the 2.5–6.0 eV energy range for undoped and Ce3+‐doped aluminium garnet (Lu3Al5O12, Y3Al5O12) and aluminium perovskite (LuAlO3, YAlO3) single crystalline films (SCF) grown by Liquid Phase Epitaxy method from the PbO‐based flux. The aim of the work was to identify spectral bands, arising from lead‐induced centers of different types, and to clarify their influence on scintillation characteristics of Ce3+ centers. It was found that in the perovskite SCF studied, the concentration of single Pb2+‐based centers is comparatively small. In the SCF of garnets, in YAG SCF their concentration is considerably smaller than in LuAG SCF. The lead‐induced emission at about 3.1–3.2 eV excited around 3.9 eV was observed in all the SCF studied and ascribed to the dimer lead centers of the type of {Pb2+ – oxygen vacancy – Pb2+}. In Ce3+‐doped perovskite SCF, due to a strong overlap of the excitation band of the dimer centers and the emission band of Ce3+ centers, a considerable influence of dimer lead centers on the scintillation characteristics of these materials is expected. In the SCF of garnets, the influence of dimer lead centers on the characteristics of Ce3+ centers is negligible. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Present study was carried out to investigate the conversion of NO by simultaneous action of the dielectric barrier discharge (DBD) and TiO 2 catalyst. NO conversion was recorded as a function of the input energy density by varying the percentage of NO and O 2 . NO conversion efficiency increased at higher content of O 2 . The presence of a TiO 2 coating inside the reactor resulted in initially enhanced NO conversion but in few minutes the positive effect of TiO 2 diminished. The increased conversion of NO in initial stage of the process was more pronounced at higher densities of input energy (higher than 100 J/l) and at lower O 2 concentrations, but without O 2 the TiO 2 coating had no effect on the conversion of NO. The results indicate that the conversion of NO during first few minutes is related to the surface reactions with adsorbed atomic oxygen.

By the investigation of the spectral characteristics of photostimulated electron emission it has been shown that F‐centres are created in NaCl, KCl, KBr, and KI single crystals by ultraviolet irradiation in the 5 to 11 eV region. The F‐centres are formed as a result of the photoproduction of excitons as well as electron–hole pairs, the exciton mechanism being especially effective. Under stimulation with visible light, electron emission appears from UV‐created F‐centres due to a two‐step photothermal process in crystals with sufficiently low electron affinity χ and by the usual photoemission mechanism in crystals with relatively high χ.

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