Ni-Cr oxide thin films were prepared by magnetron sputtering of a NiO-Cr2O3 (1:1 mol ratio) composite target. In addition to argon, oxygen was used as a reactive sputtering gas. The dependence of the partial pressure ratio (R) of oxygen to the total sputtering gas on the structural and electrical properties of the films was investigated. With an increase in R, the intensity of the X-ray diffraction peaks as associated with the Ni-O crystal structure increased and the resistivity of the films decreased. From the viewpoint of applying these films to infrared sensors, their thermistor constant B obtained from their temperature dependence of resistivity was examined. B tended to increase with R. Relatively low resistivity values and high B values were obtained in the range of R around 8%. (C) 2011 Elsevier B.V. All rights reserved.