Negative thermal expansion and electrical properties of α-Cu2V2O7
Negative thermal expansion and electrical properties of α-Cu2V2O7
复制标题
DOI：
10.1016/j.jeurceramsoc.2016.04.030
复制
发表时间：
2016-09
影响因子：
5.7
通讯作者：
Niu Zhang;Li Li-Li;Ming-Yi Wu;Lin Yuxiang;Dongsheng Feng;Cunyuan Liu;Yanchao Mao;Juan Guo;M. Chao;E. Liang
中科院分区：
文献类型：
--
作者：
Niu Zhang;Li Li-Li;Ming-Yi Wu;Lin Yuxiang;Dongsheng Feng;Cunyuan Liu;Yanchao Mao;Juan Guo;M. Chao;E. Liang
采用固相法合成了斜方钒酸铜(α-Cu2V2O7)，并系统研究了其负热膨胀(NTE)和电性能。结果表明，α-Cu2V2O7 在室温 (RT) 至 470 K 范围内表现出线性 NTE 特性，热膨胀系数 (CTE) -5.8 × 10−6K−1。由桥氧原子横向振动引起的刚性单元模式（RUM）的耦合旋转归因于 NTE 行为。此外，NTE特性在470–610 K范围内表现出非线性，平均CTE约为-2.4 × 10−6K−1，这是由Cu2+的d9Jahn-Teller效应和少量微孔的综合作用引起的。该材料在 610 至 720 K 之间表现出较低的热膨胀性，CTE 为 0.43 × 10−6K−1。紫外可见吸收光谱证实了畸变效应。阻抗谱分析表明α-Cu2V2O7具有一定的半导体性质，这与从头计算的结果一致。 NTE性能和热导率在复合导电陶瓷和高温导电材料中带来了良好的潜在应用。
The orthorhombic copper(II) vanadate (α-Cu2V2O7) was synthesized using a solid state method, and its negative thermal expansion (NTE) and electrical properties were systematically studied. The results show that the α-Cu2V2O7exhibits NTE property linearly from room temperature (RT) to 470 K with the coefficient of thermal expansion (CTE) −5.8 × 10−6K−1. The coupling rotation of rigid unit modes (RUMs) caused by transverse vibrations of bridge oxygen atoms is attributed to the NTE behavior. Moreover, NTE property performs nonlinearity in 470–610 K, and the average CTE is about −2.4 × 10−6K−1which is caused by the synthetic action of d9Jahn-Teller effect of Cu2+and small amount of micro-pores. The material exhibits low thermal expansion between 610 and 720 K with CTE 0.43 × 10−6K−1. The distortion effect was confirmed by UV–vis absorption spectroscopy. The impedance spectroscopy analysis shows that the α-Cu2V2O7has a certain semiconductor property, which is consistent with the results of ab-initio calculation. The NTE property and pyroconductivity bring a good potential application in composite conductive ceramic and high temperature conductive materials.