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This paper reports an optical investigation of Eu 3? :PbF 2 nanocrystals distributed into silica glasses fabricated by sol-gel methods. The sample microstructure was investigated using scanning transmission electron microscopy. The b-cubic PbF 2 crystalline phase was identified using X-ray diffraction analysis. The observed emission bands correspond to 5 D 0 ? 7 F J (J = 0-4) transitions of Eu 3? . The spectroscopic parameters for Eu 3? ions were determined based on excitation and emission measurements as well as luminescence decay analysis. Emission originating from 5 D 0 state of Eu 3? ions in sample containing PbF 2 nanocrystals is long-lived in comparison to precursor sol-gel silica glasses.

GdF3 nanocrystals doped with Eu3+ ions in oxyfluoride glass ceramics were prepared by a solgel method. The structural properties were examined by x-ray diffraction measurements. The effects of gadolinium codoping on europium emission in the prepared solgel glasses and glass ceramics have been studied. The emission bands originating from the 5D0 state of Eu3+ ions are enhanced under excitation of Gd3+ ions by 273 nm line. The electric dipole 5D0→7F2 transitions were dominant in the samples before heat treatment, whereas magnetic dipole 5D0→7F1 transitions had a higher probability in the samples after annealing. The luminescence lifetime for the 5D0 level of Eu3+ ions in the samples after excitation at 273 nm is long lived in comparison to excitation at 393 nm and increased to 190%. Energy transfer from Gd3+ to Eu3+ was observed.

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