NdCoO3 perovskite as possible candidate for CO-sensors:: thin films synthesis and sensing properties

In this paper the preparation of neodymium cobaltite (NdCoO3) thin films by means of rf-magnetron sputtering is presented. The sensing properties towards the CO were analyzed by following the resistivity response when changing the gas composition from air to air with CO. Measurements have shown a good response in the temperature range between 250 and 400 degrees C for CO concentration until 1000 ppm. Measurable resistance changes are accomplished within few minutes after gas switch. The optimal working temperature was found to be around 300 degrees C by taking into account the amount of resistance variation and the time required to achieve an easily measurable response for different temperatures and CO concentrations. In order to explain the results obtained, a possible model for the NCO response mechanism towards CO is presented. (c) 2004 Elsevier B.V. All rights reserved.