Solution synthesis and kinetic analyses of the gas sensing characteristics of magnesium ferrite particles

As an effective alternative of simple binary oxides, cubic spinel ferrites are also attractive for sensing reducing gases. We have focused the present work on the investigation of the hydrogen and carbon monoxide gas sensing characteristics of cubic spinel nano-crystalline magnesium ferrite powders. The semi-conducting (n-type) magnesium ferrite powders have been synthesized using an economic wet chemical synthesis route. The phase formation behavior and microstructure of the synthesized material are characterized by infra-red spectroscopy in conjunction with Reitveld refinement of X-ray diffractograms and scanning electron microscopy studies. A gas sensing reactor, equipped with automated gas flow controllers and data acquisition system, has been used to evaluate the gas sensing characteristics of the synthesized materials under dynamic flow of gases. The response and recovery transients of the conductance of the magnesium ferrite sensing elements are found to follow the Langmuir adsorption kinetics.