Copper ferrite-yttrium oxide (CFYO) nanocomposite as remarkable humidity sensor

In the present research paper, enhancement in humidity sensing properties of copper ferrite (CF) by mechano chemical mixing it with yttrium oxide (Y₂O₃) to form copper ferrite-yttrium oxide (CFYO) nanocomposite is discussed. The nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) techniques. Appearance of characteristic bands of both CF and Y₂O₃ with slight shifts in the FTIR spectrum of the composite indicating interaction between them and formation of the composite confirmed. Enhancement in active sites for water adsorption in the composite due to the presence of Y₂O₃ confirmed from both XRD and SEM studies. Increased agglomeration of nano sized particles and improved crystallinity of the composite as compared to those of CF confirmed from TEM studies and SAED patterns. The resistive type humidity sensing behaviour of CF and CFYO composite were studied and comparatively analyzed. The composite showed maximum sensing response of 4895 as against 110 of CF in the range 11%–97% RH. The response and recovery times of the composite were found to be 9 s and 23 s respectively while those of CF were 60 s and 90 s respectively. The CFYO sample showed stable sensing ability with a low humidity hysteresis. The sensing mechanism is discussed on the basis of chemisorption, physisorption and capillary condensation processes.