Influence of palladium on gas-sensing performance of magnesium ferrite nanoparticles

Commercial ferrites with high densities are mostly used in the electromagnetic devices, which require high temperature synthesis. In this article the gas-sensing characteristics of pure and Pd-doped MgFe2O4 powder has been discussed. The synthesis has been carried out by using a simple molten salt method. This method facilitates rapid synthesis at comparatively lower temperature enabling formation of nanostructures, suitable for the gas-sensing application. Various physicochemical techniques have been used for the characterization of samples. X-ray diffraction analysis confirmed the single-phase formation of pure and Pd-doped MgFe2O4 having crystallite size 15-20 nm. Pure MgFe2O4 showed highest responses towards liquid petroleum gas (LPG) at 350 deg. C while, on doping with Pd the highest response shifted towards lower operating temperature of ∼200 deg. C. Pure MgFe2O4 exhibited some response towards 200 ppm of LPG which markedly increased on doping of palladium (Pd). The probable mechanism is proposed to explain the selective response towards LPG.