IN-SITU PREPARATION OF EPITAXIAL TLBA2CA2CU3O9 HIGH-T-C THIN-FILMS

We report an in situ growth of epitaxial TlBa2Ca2Cu3O9 high-T-c thin f ilms. The films (thickness 80-400 nm) were prepared on LaAlO3 (100) su bstrates by laser ablation from a thallium-free BaCaCuO target in the presence of Tl2O vapor. X-ray diffraction patterns of theta-2 theta sc ans showed that the films consisted of highly oriented TlBa2Ca2Cu3O9 w ith the c axis perpendicular to the substrate surface, and phi scan me asurements indicated epitaxial growth. Scanning electron microscope an d atomic force microscope investigations showed smooth surfaces withou t platelike structures. The films had transition temperatures near 100 K. (C) 1996 American Institute of Physics.