淬火工艺对纳米前驱体三氧化钨功能陶瓷伏安特性的影响

The effect of quenching technology on the current-voltage properties of tungsten trioxide function ceramics based on the nanopowders

采用自制纳米三氧化钨粉末为原料,以淬火工艺制得纳米基三氧化钨陶瓷。通过I-V特性测量、显微结构和相结构分析,研究了在不同的温度下淬火三氧化钨陶瓷的伏安特性,结果表明较低温度淬火可以使样品的非线性系数提高到10.93,但随着淬火温度(开始淬火温度)的提高,样品的非线性系数急剧下降,当高于900℃淬火时,样品的电学行为转变为线性,非线性系数约为1。对其进行阻抗谱测量,结合相结构与电学行为的关系,认为相结构的不同造成晶界电阻及势垒的不同,改变了电输运特性,从而使其电学行为改变。

The ceramic samples were prepared by quenching at different temperatures in the air using the WO3 nanopowders as the starting materials. From the I-V measurements, the samples quenched at 800℃ exhibits varistor action with the nonlinear coefficient a=10.9. The nonlinear electrical properties sharply reduce with increasing quenching temperature, and present linear electrical behavior when quenched at 900℃. Combining the results of phase analysis and Ac impedance spectra, it is believed that the change of nonlinear electrical properties can be attributed to difference of the grain boundaries resistance or the height of barriers caused by different phase microstructure.