Polycrystalline Si1-xCrx thin films have been prepared by magnetron sputtering followed by rapid thermal annealing (RTA) for crystallization. RTA was performed at 800 degrees C for 5 min, 1200 degrees C for 30 s and 1200 degrees C for 2 min, in a N-2 flow. The magnetic hysteresis loops were observed at room temperature in all the samples except for RTA at 800 degrees C for 5 min, and the annealing caused the decrease of saturation magnetization relative to the as-grown film. X-ray diffraction spectra and Raman spectra showed that the annealing process lead the deposited amorphous film to be crystallized and CrSi2 phase formed. The magnetism of the films was determined by the competition between crystallinity and precipitation of diamagnetic CrSi2 phase. (C) 2011 Elsevier B.V. All rights reserved.