Overdoping: a suitable method to get crack-free YBa2Cu3O7-δfilms
| Autor: | A. K. Sarin Kumar, Hideomi Koinuma, Megumi Kawasaki |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Josephson effect
Materials science Condensed matter physics Scanning electron microscope Annealing (metallurgy) Doping Metals and Alloys Condensed Matter Physics Pulsed laser deposition Electrical resistivity and conductivity Materials Chemistry Ceramics and Composites Perpendicular Electrical and Electronic Engineering Cooper pair |
| Zdroj: | Superconductor Science and Technology. 14:1148-1151 |
| ISSN: | 1361-6668 0953-2048 |
| DOI: | 10.1088/0953-2048/14/12/336 |
| Popis: | One of the problems with the c-axis in-plane aligned YBa2Cu3O7-? films on different substrates is the cracking perpendicular to the c-axis, which should be avoided if such films are to be used for device applications. The devices based on the Josephson plasma phenomenon, which is a phase collective oscillation of the Cooper pair through the insulating barriers of the intrinsic Josephson junctions, requires carrier controlled (Tc = 60?K), c-axis in-plane aligned and crack-free YBa2Cu3O7-? films. Here we propose that overdoping of the YBa2Cu3O7-? films by substituting Ca at the Y site can help to produce crack free, c-axis in-plane aligned films. This would help to anneal the YBa2Cu3O7-? films at a lower oxygen partial pressure than the pristine YBa2Cu3O7-? and thus to obtain the 60?K phase with an elongated c-axis. This is because substantial oxygen incorporation into the films during annealing followed by the compression of the c-axis are the main causes of the crack formation. We designed an experiment to get crack free, 60?K phase YBa2Cu3O7-? films with the c-axis in the substrate plane and we verified our design by fabricating c-axis in-plane aligned (110) oriented Y0.7Ca0.3Ba2Cu3O7-y films on SrTiO3 (110) substrates. |
| Databáze: | OpenAIRE |
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