Investigation of Crystal Growth of the Cr₂O₃ thin films on Sapphire Substrates

抄録

The magnetoelectric Cr₂O₃ films were deposited on r- and c-cut sapphire substrates. From the results of surface roughness Ra, the substrate temperature of 580°C and the O₂ / Ar ratio of 0.25 was optimized condition. The Ra of c-oriented Cr₂O₃ film was much better, one-tenth than that of r-oriented film. In the reciprocal space mapping (RSM) around {10-110} and {1-1010} planes of the c-oriented film, substrate peak appeared rotating every 120 degrees along the □ direction with the rotation axis of the [001] direction, however, film peak appeared every 60 degrees. In the meantime, both of peaks of substrate and film were observed in the RSM around (2-2010), while no peaks appeared in the RSM around (2-208) in the r-oriented film. From those of the RSM results, the c-oriented film grew with twin crystal structure, but r-oriented film grew without twin.