Growth, optical and thermal properties of near-stoichiometric LiNbO₃ single crystal

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• 作者：Shuhua Yao ; Jiyang Wang ; Hong Liu ; Xiaobo Hu ; Haijin Zhang ; Xiufeng Cheng ; Zongcheng Ling
• 关键词：Single crystal growth ; Lithium niobate ; Anisotropy ; Thermal analysis
• 刊名：Journal of Alloys and Compounds
• 出版年：2008
• 出版时间：8 May 2008
• 年：2008
• 卷：455
• 期：1-2
• 页码：501-505
• 全文大小：472 K

文摘

A near-stoichiometric LiNbO₃ (N-SLN) single crystal of 40 mm in diameter and 60 mm in length has been grown by Czochralski method from a 58.5 % Li melt in a platinum crucible. The fundamental absorption edge and IR absorption spectra were used for determining Li/Nb of the crystal. The measured specific heat of the crystal to be 0.6995 J g⁻¹ K⁻¹ is larger than that of congruent LiNbO₃ (CLN) crystal to be 0.6010 J g⁻¹ K⁻¹ at 303.15 K. The thermal expansion coefficients along the two crystallographic directions in the measuring temperature range of 303.15–767.15 K have been measured to be a_a = a_b = 17.1807 K × 10⁻⁶ K and a_c = 2.8769 K × 10⁻⁶ K, respectively. Thermal conductivity of near-stoichiometric LiNbO₃ crystal is 5.234 W/m K and 4.434 W/m K at room temperature. The reason for larger anisotropic thermal expansion coefficients and larger thermal conductivity of N-SLN crystal than those of CLN crystal were discussed according to the structure of LiNbO₃ crystal.