Electrical Characteristics of HoBa 2 Cu 3 O 7-x -La 1.5 Ba 1.5 Cu 3 O 7-y -HoBa 2 Cu 3 O 7-x Junctions with Planar-Type Structures

• Published in: Japanese Journal of Applied Physics Vol. 30; no. 8R; p. 1670
• Main Authors: Kabasawa, Uki, Tarutani, Yoshinobu, Fukazawa, Tokuumi, Tsukamoto, Akira, Masahiko Hiratani, Masahiko Hiratani, Kazumasa Takagi, Kazumasa Takagi
• Format: Journal Article
• Language: English
• Published: 01.08.1991
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.30.1670

A HoBa 2 Cu 3 O 7- x -La 1.5 Ba 1.5 Cu 3 O 7- y -HoBa 2 Cu 3 O 7- x junction having a planar structure is fabricated and its electrical characteristics are investigated. The planar junction is formed by sectioning a HoBa 2 Cu 3 O 7- x layer into two superconducting electrodes keeping a submicrometer between them. Supercurrent is detected for the junction with an electrode spacing smaller than 0.4 µm. Critical current is exponentially dependent on electrode spacing. Superconducting decay length for the La 1.5 Ba 1.5 Cu 3 O 7- y layer is 65 nm and is almost independent of temperature up to 70 K. This extraordinary long decay length and anomalous superconducting characteristics are not shown to be explained by the conventional proximity theory, and phenomenologically outlined.