LAUSR

In the present work (0–20%) Mn doped NiO, (10–20%) Ni doped Mn3O4, and composite NiO/Mn3O4 nanoparticles were synthesized using the solid state reaction method. The purity of the nanoparticles was confirmed using x-ray diffraction (XRD) study. Scanning electron microscope (SEM) images confirmed the formation of irregularly shaped nanoparticles with an average diameter of 50–100 nm. Then humidity sensors based on these nanoparticles were fabricated and tested. The doping up to certain content enhanced the sensitivity, and the maximum sensitivity of 70% was observed for 10% Ni doped Mn3O4. These sensors exhibited reasonably fast response and recovery times and were better or comparable to those of similar materials. Therefore nickel/manganese oxide nanoparticles are suitable for use in fabrication of humidity sensors.