Ethanol-sensing properties of SmFe1-xNixO3 perovskite oxides

SmFe1-xNixO3 (x <= 0.3) nanocrystallite powders with orthorhombic Structure were prepared by a sol-gel citric method. The average crystallite sizes of SmFe1-xNixO3 powders are about 10-30 nm. The influences of Ni dopants upon electrical and ethanol-sensing properties of SmFe1-xNixO3 sensors are investigated. Compared with SmFeO3, SmFe1-xNixO3 (0<= 0.3) present higher conductivities and lower optimal operating temperatures. The highest response to 500ppm ethanol gas reaches 57.8 at 260 degrees C for SmFe0.95Ni0.05O3 sensor, with the response- and recovery-time of 30s and 50s, respectively. In addition, the SmFe0.95Ni0.05O3 sensor exhibits a good selectivity to ethanol. However, the high Ni dopants in SmFe1-xNixO3 (x > 0.05) seriously degrade the sensing sensitivities. (C) 2009 Elsevier B.V. All rights reserved.