Growth Spirals Appeared in c-Axis Oriented YBCO Films Grown on MgO Substrate by Sputtering |
| T. Suzuki, K. Azechi, S. Sakurai and S. Aizawa Nippon Institute of Technology, Miyashiro, Minami-Saitama, Saitama 345, Japan |
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| The early stages of growth and the evolution of surface microstructure of epitaxial c-axis YBa2Cu3O7-x thin films were studied as a function of film thickness, growth temperature, and growth rate. The films were grown in situ on as-polished or annealed MgO(100) substrates by off-axis magnetron sputtering. Atomic force microscopy was used to observe the surface microstructure. From the results at early stages, we proposed a growth model of spirals for the films grown on as-polished substrate, i.e. spirals are formed around the surface roughness of the substrate. Growth temperature and growth rate dependence on the density of spirals support this model. That is, the density of spirals does not change according to the change of growth temperature (600-740°C) or growth rate (7-80 nm/h). |
| DOI: 10.12693/APhysPolA.92.215 PACS numbers: 74.76.Bz, 74.72.Bk, 68.55.-a |