Humidity Sensor Using Sintered Sb<SUB>2</SUB>ZrO<SUB>x</SUB>

Abstract

The humidity-dependent impedance of sintered Sb2ZrOx was studied. Most of the open pore are throughpores. The volume of voids, average pore radius, and average particle size were estimated to be 0.21 cm3·cm-3, 2×10-6, and 1×10-5cm, respectively. No distinct peaks could be detected in x-ray diffraction patterns. In the high humidity region (P/P0>0.2), it was found that the impedance is expressed as Z=Z0exp(-Eapp/kT*)exp(Eapp/kT). The decrease of Eapp with an increase in the amount of adsorbed water was interpretable in terms of the decrease in Coulomb interaction for carrier (proton) formation. In addition, the value of Eapp in high coverage region (θ>2.5) was in fair agreement with that in liquid water trapped from the ambient air.