Microwave surface resistance of YBa2Cu3Oy films covered by overdoped Y1-xCaxBa2Cu3Oy layers

Citation
H. Obara et al., Microwave surface resistance of YBa2Cu3Oy films covered by overdoped Y1-xCaxBa2Cu3Oy layers, APPL PHYS L, 78(5), 2001, pp. 646-648
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
78
Issue
5
Year of publication
2001
Pages
646 - 648
Database
ISI
SICI code
0003-6951(20010129)78:5<646:MSROYF>2.0.ZU;2-4
Abstract
We have observed the reduction of the microwave surface resistance R-s of Y Ba2Cu3Oy films deposited on MgO substrates by covering the films with an ov erdoped Y1-xCaxBa2Cu3Oy layer. At low temperature, R-s of the YBa2Cu3Oy fil m covered by an Y1-xCaxBa2Cu3Oy (x=0.2) layer was half that of the single Y Ba2Cu3Oy film. On the other hand, the single Y1-xCaxBa2Cu3Oy (x=0.2) films did not exhibit low loss characteristics. The diffusion of Ca ions into the YBa2Cu3Oy layer was observed and the selective diffusion of Ca ions to the grain boundaries of the YBa2Cu3Oy layer is considered to be the origin of the low R-s in the covered YBa2Cu3Oy films. (C) 2001 American Institute of Physics.