Microstructure of c-axis oriented lead titanate thin films by pulsed laser ablation

Epitaxial ferroelectric PbTiO3/YBa2Cu 3O7-x heterostructures have been fabricated on [001] LaAlO3 by pulsed laser ablation. X-ray diffractometer scans showed only the (00l) peaks from the lead titanate and YBa2Cu 3O7-x film indicating c-axis growth. Transmission electron microscopy on planar and cross-sectional samples revealed a single domain film. The c-axis orientation in the lead titanate film is ascribed to the good lattice match of the a-axis of lead titanate with the a- or b-axes of the YBa2Cu3O7-x film. A cubic lead titanate film is deposited above the Curie point. Compressive stresses arise in the lead titanate film due to lattice mismatch. The c-axis orientation is favored since it reduces the compressive residual stresses.