Gas sensing properties of In2−xMnxO3−δ

Abstract

Nominal compositions of general formula In2−xMnxO3−δ were prepared by solid-state route and their electrical conductivity and hydrogen sensing characteristics were investigated. With manganese addition, the conductivity was found to increase initially and then decrease while the activation energy for the conduction process was increasing. In1.99Mn0.01O3-δ, In1.985Mn0.015O3-δ, In1.98Mn0.02O3-δ were found to sense 100 vppm to 2 % of hydrogen at 623 K. Preliminary results indicated the possibility of two types of gas sensing mechanisms operating at low and high concentrations of hydrogen in air.