Ammonia sensing properties of thick and thin films of Ag₆Mo₁₀O₃₃ and Cr_1·8Ti_0·2O_3+<i>δ</i>

Abstract

Thick film of silver decamolybdate (Ag 6 Mo 10 O 33 ) was screen printed and thin film of chromium titanate Cr 1·8 Ti 0·2 O 3+ δ was laser deposited on alumina substrates. Morphological features of the films were characterised and ammonia sensing properties were studied. Resistance of Ag 6 Mo 10 O 33 thick films decrease on introduction of NH 3 gas and these films were capable of sensing 2 ppm of ammonia in air at 578 K. Cr 1·8 Ti 0·2 O 3+ δ thin films could sense 20 ppm of ammonia in air at 673 K, which exhibited increase in resistance towards NH 3 gas.