Published online by Cambridge University Press: 25 February 2011
The initial stages of epitaxial growth of laser ablated YBa2Cu3O7-δ (YBCO) thin films on (001) SrTiO3, LaAlO3, and MgO substrates, and on slightly miscut LaA1O3 and SrTiO3, have been studied with scanning tunneling microscopy (STM). Surface images show that the initial YBCO growth mode can be either of the Stranski- Krastanov or the Volmer-Weber type, depending on the film-substrate lattice mismatch and the growth temperature. A small substrate miscut angle is found to strongly influence the growth mode of YBCO films. Screw dislocation-mediated growth is suppressed, and films grown at 800°C on (001) LaAlO3 substrates with miscut angle of 2.0° along <100> or <110> directions were found to consist of tilted platelets that are epitaxially aligned with the substrate crystal lattice.