Title :
Properties of epitaxially grown A-axis oriented YBa2 Cu3O7-x-PrBa2Cu3O 7-y heterostructures
Author :
Inam, A. ; Ramesh, R. ; Rogers, C.T. ; Wilkens, B. ; Remschnig, K. ; Hart, D. ; Barner, Jeff
Author_Institution :
Bellcore, Red Bank, NJ, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
Multilayer structures of YBa2Cu3O7-x -PrBa2Cu3O7-y were prepared, using pulsed laser deposition, with the a-axis oriented normal to the surface of a variety of (001) substrates. Structural characterization of these films by X-ray diffraction, transmission electron microscopy, and helium ion beam channeling reveal a highly ordered microstructure similar, if not better, in quality to that obtained in the best c-axis-oriented films. Studies of the surface morphology by scanning electron microscopy show a very smooth surface with a total absence of the outgrowths commonly seen in c-axis-oriented films. It is observed that while the a-axis-oriented films grown on (001) substrates show no a-b axis twinning, the films are composed of 0.01-0.1-μm-sized domains that have the Y(Pr)Ba2Cu3O7-x c-axis oriented along the substrate (100) or (010) in-plane direction. Superconducting transition temperatures, for current transport in the plane of the films, consistently exceed 80 K and are found to increase with the size of the domains
Keywords :
X-ray diffraction examination of materials; barium compounds; critical current density (superconductivity); high-temperature superconductors; praseodymium compounds; scanning electron microscope examination of materials; superconducting epitaxial layers; superconducting transition temperature; superconductive tunnelling; transmission electron microscope examination of materials; yttrium compounds; (001) substrates; X-ray diffraction; YBa2Cu3O7-x-PrBa2Cu 3O7-y heterostructures; a-axis oriented normal; domains; high temperature superconductor; highly ordered microstructure; ion beam channeling; outgrowths; scanning electron microscopy; surface morphology; transition temperatures; transmission electron microscopy; twinning; ulsed laser deposition; very smooth surface; Electron beams; Nonhomogeneous media; Optical pulses; Pulsed laser deposition; Substrates; Superconducting films; Surface emitting lasers; Surface morphology; X-ray diffraction; X-ray lasers;
Journal_Title :
Magnetics, IEEE Transactions on
