Humidity sensing properties of the sensor based on Bi0.5K0.5TiO3 powder

As a novel humidity sensing material, Bi0.5K0.5TiO3 (BKT) powder was synthesized by a chemical solution method, and the humidity sensor was composed of BKT powder, Ag–Pd interdigitated electrodes and Al2O3 ceramic substrate. The humidity sensing properties were measured by using LCR analyzer. The experimental results show that the impedance changes about four orders of magnitude within the whole humidity range from 11% to 95% relative humidity (RH). At the frequency of 100 Hz, the response time and recovery time are about 12 and 25 s, and the maximum hysteresis is around 3% RH. They indicate that BKT powder has good humidity sensing properties, and it is of the potential applications for fabricating high performance humidity sensors.