频率和温度对陶瓷湿敏元件感湿特性的影响

Effects of Frequency and Temperature on the Characteristics of Ceramic Humidity Sensitive Elements

研究了工作频率和温度对TiO2－K2O－LiZnVO4陶瓷薄膜湿敏元件感湿特性的影响．结果表明：在低湿区，元件的阻抗随频率增大、温度升高而减小，感湿灵敏度随频率增大、温度降低而显著减小，感湿特性曲线出现平台；在高湿区，频率和温度对元件感湿特性的影响可以忽略，感湿特性曲线线性良好．分析了陶瓷薄膜的极化现象，发现极化现象导致薄膜的微观电容在低温低湿时对湿度变化不敏感．据此解释了极化现象引起频率和温度对元件感湿特性影响的内在机理．

The authers studied the effects of the frequency and temperature on the TiO2-K2OLiZnVO4 ceramic thin film elements' humidity sensing characteristics. During low rh range, the impedance of the elements decreases as the frequency or temperature increases, the humidity sensitivity decreases obviously as the frequency increases or temperature decreases, and platforms appeare at the humidity sensing Characteristic curves. During high rh range, however, the effects of the frequency and temperature can be ignored, and the characteristic curves present excellent linearity. The polarization within the ceramic thin films was analyzed. The polarization causes the insensitivity of micro-capacitance versus rh at low rh and low temperature. Consequently, the mechanism of how the polarization within the ceramics resulted in the effects of frequency and temperature on the elements' characteristics was interpreted in detail.