Browsing by Author "Zhang, NN"

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
    Low temperature neutron diffraction on congruent and near stoichiometric LiNbO3
    (World Scientifice Publishing Company, 2012-08-30) Yao, SH; Sang, YH; Yu, DH; Avdeev, M; Liu, H; Wang, JY; Zhang, NN
    Neutron powder diffraction has been carried out on a congruent LiNbO(3) sample containing (7)Li isotope (C(7)LN) and a near stoichiometric Mg doped LiNbO3 sample (Mg: NSLN) in the temperature range of 4 K and 90 K. Large anisotropic displacement parameters (ADPs) of the Li ions have shown evidence of large disorder along the c-axis for both samples. The results have shown no evidence for the existence of anomalous structural behavior for both samples at low temperatures, although abnormal structural features at 55 K and 100 K for a LiNbO3 crystal having different Li content as the samples used in the present studies have been observed by Fernandez-Ruiz et al. [Phys. Rev. B 72 (2005) 184108]. © 2012, World Scientific Publishing Co.