Preparation and characterisation of Cr2-xTixO3+delta and its sensor properties

Compounds with nominal compositions Cr2-xTixO3+delta (where x = 0.1-0.4) we re prepared by a solid state chemical reaction at 1273 K. Characterisation of the products by XRD showed the presence of a solid solution of TiO2 in C r2O3 as the major phase along with CrTiO3 as the minor phase. Conductivity studies indicated the absence of a significant influence of titanium concen tration on the activation energy (E-a) for conduction in the temperature ra nge 300-700 K in ambient air. Sensor studies showed that the compound with nominal composition Cr1.8Ti0.2O3+delta is a suitable material for sensing N H3, H-2 and LPG in ambient around 573 K. The enhanced sensitivity of this c ompound when compared with it's parent compounds, is proposed to be due to the presence of a solid solution of TiO2 in Cr2O3. (C) 1999 Elsevier Scienc e S.A. All rights reserved.