Browsing by Author "Chen, YF"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Lattice dynamics of KxRhO2 single crystals
    (AIP Publishing, 2015-08-05) Zhang, BB; Zhang, NN; Dong, ST; Lv, YY; Chen, YB; Yao, SH; Zhang, ST; Gu, ZB; Zhou, J; Guedes, I; Yu, DH; Chen, YF
    A series of crystals KxRhO2 (x = 0.72, 0.63, 0.55, 0.39, and 0.24) have been synthesized and their vibrational properties have been studied by first principles calculations, Raman spectroscopy, and inelastic neutron scattering. The measured vibrational spectra of KxRhO2 for x = 0.72 and 0.63 are consistent with the theoretical prediction for the stoichiometric KRhO2. For samples with x = 0.55, 0.39 and 0.24, extra vibrational modes have been observed and they are believed to be due to the symmetry reduction and the loss of translational symmetry induced by K disorder. The good agreement was found for the phonon density of states among the Raman spectroscopic observations, inelastic neutron scattering and the first principles calculations, as an evidence for the generation of structure disorder by K deficiency. © 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
  • No Thumbnail Available
    Item
    Mechanism of the abnormal thermal expansion of nearly stoichiometric LiNbO3
    (Elsevier Science, 2011-03-01) Yao, SH; Wang, JY; Liu, HB; Yan, T; Yu, DH; Chen, YF
    High temperature X-ray diffraction, thermal expansion and Raman spectroscopic measurements have been conducted to investigate the structural behavior of nearly stoichiometric LiNbO3. Abnormal thermal expansion has been observed within the temperature range of 1021-1373 K. The mechanism responsible for the abnormal phenomena and the structure deformation has been identified as the competition between the thermal vibration in the x-y plane and the antiphase motion along the z-axis of the [NbO6] framework as a function of temperature through the analysis of the temperature dependent Raman spectra. (C) 2010 Elsevier B.V.