Preparation and Studies on Gas Sensing Performance of Pure and Modified Sn-TiO^sub 2^ Thick Film Resistor

In this work we report the preparation, microstructure, electric properties and gas sensing performance of Sn-TiO^sub 2^ (ST) powder prepared by chemical method. The gas sensing performance of the unmodified and surface modified films was tested for various gases. The unmodified ST films showed temperature programmed sensitivity. Unmodified ST films could select different gases at different operating temperatures for ex. it selects H^sub 2^ at 250 °C, H^sub 2^S at 300 °C, Cl^sub 2^ at 350 °C and LPG at 400 °C. As prepared films were modified by dipping technique by using NiCl^sub 2^ precursor solution. These surface modified ST films showed response to only H^sub 2^ (800 ppm) gas. Surface modification of the ST thick films, altered the adsorbate-adsorbent interactions, which gave the unusual selectivity and sensitivity effect. The characterization of the films was done by XRD, SEM and TGA. The sensitivity, selectivity, of the ST thick films were measured and presented. [PUBLICATION ABSTRACT]