Variation of the preferred orientation with thickness in barium titanate thin films prepared by pulsed laser deposition

In the deposition of BaTiO3 thin films by pulsed laser deposition, the variation of the preferred orientation with thickness was studied. The preferred orientation of the films deposited below 1 mTorr was (100), and did not change with variations in the thickness due to the high adatom mobilities. The preferred orientation of the films deposited above 200 mTorr was (110) which has the highest growth rate in the BaTiO3 perovskite structure, and it did not also change with variations in thickness. During the deposition between 50-100 mTorr, the preferred orientation varied in the order of (111)-(110)-(111) with an increase in the thickness of the film. For this orientation change to occur, the film surface should be rough. This preferred orientation change was thought to be related to the (111) twins of BaTiO3.