Abstract
Interfaces between a sapphire ( R-Al 2O 3) substrate, a CeO 2 buffer layer, and a YBa 2Cu 3O 7− δ (YBCO) layer — both layers obtained by MOCVD — have been studied by high-resolution electron microscopy. Lattice parameter mismatch between the sapphire substrate and the CeO 2 layer was observed to be accommodated within the first one or two atomic planes of the CeO 2 layer. The density of misfit dislocations correlated well with the mismatch between the CeO 2 and sapphire unit cell parameters. Small imperfections in the sapphire surface were observed not to lead to a change in orientation of the overlying CeO 2 layer, nor to an increased roughness of the CeO 2 surface. The roughness of the CeO 2 surface was found to be considerably less than that of the sapphire surface. The YBCO/CeO 2 interface contained only a small number of dislocations, located in the YBCO layer. Steps in the CeO 2 surface were observed to be accommodated by antiphase boundaries, or planar defects close to the interface.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
