Graphoepitaxy of ceo2 on mgo and its application to the fabrication of 45-degrees grain-boundary josephson-junctions of yba2cu3o7-x
Copetti, C.A. × Schubert, J. Klushin, A.M. Bauer, S. Zander, W. Buchal, C. Seo, Jin Won Sanchez, F. Bauer, M. #
Amer inst physics
Journal of Applied Physics vol:78 issue:8 pages:5058-5061
We communicate a detailed study of the epitaxial growth of CeO2 on MgO. The key feature of the growth is the dependence of the in-plane orientation of the CeO2 epitaxial layer on the MgO surface morphology. Atomic force microscopic (AFM) measurements, x-ray analyses, as well as high-resolution transmission electron microscopy (HRTEM) investigations reveal that on rough substrates a cube-on-cube growth of CeO2 on MgO occurs while on smooth substrates the CeO2 unit cell is rotated around the surface normal by 45 degrees with respect to the MgO unit cell when the deposition rate is low (similar to 0.3 Angstrom/s) during the first stages of growth. This growth mechanism can be used for a defined fabrication of 45 degrees grain boundaries in the CeO2 layer by controlling the surface roughness of the MgO substrate. This report demonstrates that these 45 degrees grain boundaries may be used to fabricate YBa2Cu3O7-x Josephson junctions. (C) 1995 American Institute of Physics.