论文信息 - Nanocrystalline SrTiO3:Eu3+ and BaTiO3:Eu3+: fluorescence spectroscopy and optical studies of structural phase transitions

Nanocrystalline SrTiO3:Eu3+ and BaTiO3:Eu3+: fluorescence spectroscopy and optical studies of structural phase transitions

The results of optical studies of Eu3+ ions doped nanocrystalline materials which undergo structural phase transitions: SrTiO3:Eu3+ and BaTiO3:Eu3+ are presented. Nanocrystalline SrTiO3 and BaTiO3 samples with crystallite sizes about 25–50 nm were produced by the sol-gel process. The Eu3+ 5D0,1 7Fn fluorescence spectra were studied. Time-resolved fluorescence spectra enabled to separate different kinds of Eu3+ centers in BaTiO3 samples. Fluorescence spectroscopy of probe Eu3+ ions was used to detect the structural Oh – D4h phase transition in nanocrystalline SrTiO3. The Eu3+ excited states lifetimes were studied in a wide temperature range and the effects of modified refractive index of the media on radiative transitions were observed. The study of ferroelectric C4v – Oh phase transition in nanocrystalline BaTiO3 with optical second harmonic generation technique revealed remarkable hysteresis in the temperature dependence of the second harmonic intensity. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

R. I. Zakharchenya | A. A. Kaplyanskii | S. Feofilov | A. Kulinkin

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