Browsing by Author "Yan, T"

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    Formation mechanism of black LiTaO3 single crystals through chemical reduction
    (Wiley-Blackwell, 2011-02-01) Yan, T; Zheng, FF; Yu, Y; Qin, SB; Liu, H; Wang, JY; Yu, DH
    Lithium tantalate (LiTaO3, LT) wafers of different colors were prepared through chemical reduction of regular congruent LT wafers. Samples with different colors corresponding to different annealing temperatures were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and measurements of the Curie temperature and density. It was found that chemical reduction does not influence the basic LT structure. The Ta charge state change due to chemical reduction was found to be the main reason for the formation of black LT wafers.© 2011, Wiley-Blackwell
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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.