Structure, microstructure, and enhanced sensing behavior of nickle ferrite–cobalt chromate for humidity sensor applications

Humidity sensing properties of NiFe 2 O 4 /CoCr 2 O 4 nanocomposites ceramics were reported for the first time through chemical synthesis and mechanical mixing methods. The interaction of CoCr 2 O 4 and NiFe 2 O 4 was analyzed through X-ray diffraction, and the morphology of the samples was studied with Field emission scanning electron microscopy(FESEM). The results indicate that nonmetal elements act as interstitial ones to form the composite. As the amount of NiFe 2 O 4 increased, the morphology of the nanocomposites changed from near-spherical to irregular cube-like shapes, with their particle sizes increasing over 10 nm. We studied elemental analysis using the EDX technique. Additionally, the resistance and humidity sensing responses become more noticeable, with desorption occurring slower than adsorption. The sensor takes 10 s to react and 15 s to recover. These findings provide a potential approach to creating large-scale chromate–ferrite composites and improving their structural, morphological, and humidity sensing properties, making them excellent candidates for humidity sensor applications.