高溫高壓水熱法合成鹼金屬碲酸鹽及其結構與性質研究;High-Temperature, High-Pressure Hydrothermal Synthesis, Structures and Properties of Alkali Metal Tellurites

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/83195

Title:	高溫高壓水熱法合成鹼金屬碲酸鹽及其結構與性質研究;High-Temperature, High-Pressure Hydrothermal Synthesis, Structures and Properties of Alkali Metal Tellurites
Authors:	王綉婷;Wang, Hsiu-Ting
Contributors:	化學學系
Keywords:	鹼金屬碲酸鹽
Date:	2020-07-16
Issue Date:	2020-09-02 15:07:08 (UTC+8)
Publisher:	國立中央大學
Abstract:	利用非線性光學 (Nonlinear optics, 簡稱 NLO) 晶體所轉換的雷射光能應用於雷射切割、醫療和通訊等眾多領域，故開發良好的非線性光學晶體具有一定的重要性。本研究利用高溫高壓水熱法合成出KLiTi3Te3O13 (A1)，利用高溫高壓水熱法與中溫水熱法皆可合成出KLiTe4O9(H2O)4.5 (A2)，並藉由單晶X光繞射、紅外線光譜、能量色散X-射線光譜以及熱分析確定這兩個化合物的晶體結構與元素組成，再利用粉末X光繞射確定樣品純度。A1化合物為針狀晶體，空間群屬於中心對稱的Ibam，其結構由 [TiO6] 利用反式共角方式形成無限延伸的一維鏈狀以及 [TiO6] 藉由共邊和共角方式形成的二維層狀，沿著 b 軸方向交錯排列，再藉由 [TeO3] 交聯去組成三維網狀結構，並比較Ti-O層與銳鈦礦 (二氧化鈦的其中一種礦物形式) 的結構差異。 A2化合物為片狀晶體，空間群為中心對稱的C2/c ，屬於二維層狀結構，每一層都是由 [TeO3], [TeO4] 藉由共角方式所形成的星型、船型六元環組成，鹼金屬陽離子和水分子則會坐落在層與層之間，並比較A2化合物與其他幾種相關化合物的結構差異。;The laser light converted by nonlinear optics (NLO) crystals has applications in many fields such as laser cutting, medical, and communication. Therefore, it is essential to develop good nonlinear optical crystals. In this study, KLiTi3Te3O13 (A1) was synthesized by high-temperature, high-pressure hydrothermal method, and KLiTe4O9(H2O)4.5 (A2) was synthesized by both high-temperature, high-pressure hydrothermal method and medium-temperature hydrothermal method. Their crystal structures and compositions were determined by a combination of techniques including single-crystal X-ray diffraction, infrared and energy dispersive spectroscopy, and thermal analysis. A1 crystalizes as needle-like crystals in the centrosymmetric orthorhombic space group Ibam. Its structure is formed of infinite chains of trans-corner sharing TiO6 octahedra and layers of edge-sharing TiO6 octahedra, which are cross-linked by TeO3 ligands to form a 3D framework. The structure of Ti-O layer is compared with that of the mineral anatase. A2 crystalizes as lamellar crystals in the centrosymmetric space group C2/c and has a 2D layer structure. Each layer is formed of corner-sharing TeO3 and TeO4 unis with two types of six-membered rings. The alkali metal cations and water molecules are located between the layers. Its crystal structure is compared with several related compounds.
Appears in Collections:	[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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