Spectroscopic study of Co-doped BaTiO3 thin films

Co-doped BaTiO3 thin films with the perovskite structure were prepared by p yrolysis of metalorganic compounds. According to optical-absorption and lum inescence data, the introduction of Co had an insignificant effect on the C urie temperature T-C of the films (about 120 degrees C), presumably because of the competitive effects of the Co dopant, reducing T-C, and the large c ompressive strain due to the thermal expansion mismatch, raising T-C. An ab sorption band tentatively attributed to a small-radius polaron was observed in the near-infrared spectral region.