In situ preparation of epitaxial TlBa2Ca2Cu3O9 high-T-c thin films

We report an in situ growth of epitaxial TlBa2Ca2Cu3O9 high-T-c thin films. The films (thickness 80-400 nm) were prepared on LaAlO3 (100) substrates by laser ablation from a thallium-free BaCaCuO target in the presence of Tl2O vapor. X-ray diffraction patterns of theta-2 theta scans showed that the films consisted of highly oriented TlBa2Ca2Cu3O9 with the c axis perpendicular to the substrate surface, and phi scan measurements indicated epitaxial growth. Scanning electron microscope and atomic force microscope investigations showed smooth surfaces without platelike structures. The films had transition temperatures near 100 K. (C) 1996 American Institute of Physics.