BLOCK-BY-BLOCK DEPOSITION - A NEW GROWTH METHOD FOR COMPLEX OXIDE THIN-FILMS

An alternative growth method for high-T(c) oxide thin films employing molecular beam deposition is proposed. Instead of an uncontrolled local nucleation followed by lateral growth and island coalescence, the new method provides substrate coverage by nonreacting constituents before nucleation is initiated, a controlled reaction path, and reduced lateral growth. DyBa2Cu3O6+delta films without precipitates, with a surface roughness of +/- 1 unit cell and showing finite size oscillations in the x-ray diffraction spectrum, have been prepared. This method reveals that diffusion dominates the growth process at high substrate temperatures (congruent-to 700-degrees-C).