Preparation and humidity sensing behavior of cadmium - Zinc ferrite nanocomposite

Abstract

Cadmium Zinc ferrite (Cd0.8Zn0.2Fe2O4) nano-composites (NC) were prepared by auto-combustion method, and annealed at 650 C. The humidity sensing behavior of this composite has been studied. The ability of a ferrite to sense the ambient water molecules depends on their interaction with ferrite material's porous surface. The Cd0.8Zn0.2Fe2O4NC samples exhibit a high value of sensitivity to humidity, equal to 1.483 M?/%RH; this high sensitivity is due to two reasons. The first reason for this is the porous morphology of the prepared NC samples, confirmed from the SEM images. The second reason is the low value of crystallite size as more active sites for adsorption and desorption of water molecules become possible when the crystallite size is reduced. The humidity sensing behavior of the prepared composite films, based on electrical impedance measurements, exhibit an excellent reproducibility of 98%, as well as good response and recovery times of 86 seconds and 44 seconds, respectively. Therefore, it is a good candidate for humidity sensing applications.