Synthesis and tunable thermal expansion properties of Sc_{2鈭?span style='font-style: italic'>x}Y_xW₃O₁₂ solid solutions

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• 作者：Qinqin Liu ; ^{liu_qin_qin@126.com" class="auth_mail} ; Zengqiang Yu ; Gaofa Che ; Jinliang Yao ; Xiujuan Sun ; Xiaonong Cheng ; Juan Yang
• 关键词：C. Thermal expansion ; Tungstate ; Solid solution ; Sc2&minus ; xYxW3O12
• 刊名：Ceramics International
• 出版年：July, 2014
• 年：2014
• 卷：40
• 期：6
• 页码：8195-8199
• 全文大小：1888 K

文摘

A new series of rare earth solid solutions Sc_2鈭?em>xY_xW₃O₁₂ was successfully synthesized by the conventional solid-state method. Effects of doping ion yttrium on the crystal structure, morphology and thermal expansion property of as-prepared Sc_2鈭?em>xY_xW₃O₁₂ ceramics were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TG), field emission scanning electron microscope (FE-SEM) and thermal mechanical analyzer (TMA). Results indicate that the obtained Sc_2鈭?em>xY_xW₃O₁₂ samples with Y doping of 0鈮?em>x鈮?.5 are in the form of orthorhombic Sc₂W₃O₁₂-structure and show negative thermal expansion (NTE) from room temperature to 600 掳C; while as-synthesized materials with Y doping of 1.5鈮?em>x鈮? take hygroscopic Y₂W₃O₁₂路nH₂O-structure at room temperature and exhibit NTE only after losing water molecules. It is suggested that the obvious difference in crystal structure leads to different thermal expansion behaviors in Sc_2鈭?em>xY_xW₃O₁₂. Thus it is proposed that thermal expansion properties of Sc_2鈭?em>xY_xW₃O₁₂ can be adjusted by the employment of Y dopant; the obtained Sc_1.5Y_0.5W₃O₁₂ ceramic shows almost zero thermal expansion and its average linear thermal expansion coefficient is 鈭?.00683脳10^鈭? 掳C^鈭? in the 25-250 掳C range.