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

Abstract
Epitaxial ferroelectric PbTiO3/YBa2Cu3O7−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 YBa2Cu3O7−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.