Synthesis process induced improvement on the gas sensing characteristics of nano-crystalline magnesium zinc ferrite particles

The gas sensing performances of the ferrite based sensors can be improved by modifying their surfaces to volume ratio, grain size, morphology and meso-porous nature. Synthesis of phase pure ferrites with desired micro-structural features at lower calcinations temperature remains a challenging task. In order to improve their gas sensing performance, in the present work we have investigated the (synthesis) process induced modifications of the phase and micro-structural features of wet chemical synthesized ferrite sensing elements. We have synthesized Mg0.5Zn0.5Fe2O4 (MZFO) particles through poly vinyl alcohol assisted wet chemical synthesis route (MZFO-P) and citrate based modified Pechini process (MZFO-C). The phase formation behavior, micro-structural characteristics and surface area estimation of the particles are performed using X-ray diffraction, electron microscopy and N-2 adsorption-desorption isotherm analyses respectively. It is demonstrated that as compared to MZFO-P. MZFO-C nano-particles are phase pure with smaller particle size, larger specific surface area, and meso-porous surface morphologies. These structural and micro-structural features are found to have significant influence on the gas sensing performances of Mg0.5Zn0.5Fe2O4 particles prepared using two different wet chemical routes. (C) 2011 Elsevier B.V. All rights reserved.