Browsing by Author "Yao, SH"

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    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.
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    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.