Title :
Microstructural study in heteroepitaxial YBa2Cu3O7/Nd2CuO4 multi-layers by using electron microscopy
Author :
Gao, J. ; Cheung, Y.L. ; So, S.M.
Author_Institution :
Dept. of Phys., Univ. of Hong Kong, China
fDate :
6/1/2003 12:00:00 AM
Abstract :
Neodymium copper oxide Nd2CuO4 (NCO) has been applied as a buffer material to improve the epitaxy of YBa2Cu3O7 (YBCO) thin films on reactive substrates and as a potential barrier to construct multi-layer junctions. The microstructures and interfaces in heteroepitaxial Nd2CuO4/YBCO multi-layer have been characterized by using an electron microscopy. Cross-sectional images obtained on a transmission electron microscopy (TEM) revealed an atomically sharp boundary between layers, underlining the excellent compatibility of NCO with YBCO. No chemical reaction occurred between film and substrate. It was found that all layers grow highly epitaxially with their c-axis perpendicular to the substrate surface. On the other hand, various defects such as mis-oriented grains and stacking faults were found near the interfaces.
Keywords :
barium compounds; crystal microstructure; high-temperature superconductors; interface structure; neodymium compounds; stacking faults; superconducting superlattices; transmission electron microscopy; yttrium compounds; TEM; YBa2Cu3O7-Nd2CuO4; atomically sharp boundary; electron microscopy; heteroepitaxial YBa2Cu3O7/Nd2CuO4 multi-layers; high temperature superconductor; interfaces; microstructures; misoriented grains; potential barrier; reactive substrates; stacking faults; Atomic layer deposition; Chemicals; Electron microscopy; Epitaxial growth; Microstructure; Neodymium; Substrates; Transistors; Transmission electron microscopy; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.814059
