Fabrication and Characterization of Bi-epitaxial Grain Boundary Junctions in YBa2Cu3O7δ

Kazuya KINOSHITA  Syuuji ARISAKA  Takeshi KOBAYASHI  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E76-C   No.8   pp.1265-1270
Publication Date: 1993/08/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on High-Temperature Superconducting Electronics)
Category: 
Keyword: 
YBa2Cu3O7δ,  SrTiO3,  bi-epitaxial grain boundary junction,  Josephson junction,  

Full Text: PDF>>
Buy this Article




Summary: 
We have fabricated bi-epitaxial grain boundary junctions in YBa2Cu3O7δ (YBCO) thin films by using SrTiO3 (STO) seed layers on MgO(100) substrate. YBCO film growing over the STO seed layer has a different in-plane orientation from YBCO film without the seed layer, so artificial grain boundaries were created at the edge of the seed layer. The fabricated junctions have high Tc (up to 80 K), and constant-voltage current steps are observed in response to 12.1 GHz microwave radiation. Moreover, some of the junctions show characteristic current-voltage curves comprising not only an usual Josephson-like characteristic but also a low critical current due to the flux creep. This suggests that the two characteristic parts are likely to be connected in series at the junction region.