In situAg/YBa2Cu3O7contacts for superconductor–normal-metal–superconductor devices

Autor: Alan Willis Kleinsasser, Roger H. Koch, R. P. Robertazzi, K. G. Stawiasz, Robert B. Laibowitz
Rok vydání: 1992
Předmět:
Zdroj: Physical Review B. 46:8456-8471
ISSN: 1095-3795
0163-1829
DOI: 10.1103/physrevb.46.8456
Popis: By use of a completely in situ process, we have investigated Ag metal contacts to thin films of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ (YBCO), in order to study the properties of the Ag/YBCO interface as well as the Josephson effect in SNS bridges made with this technique. Measurements of the temperature dependence of the Josephson current in these devices have been made, and are compared to recent theoretical predictions. SNS devices which exhibited Josephson effects had the critical current--resistance (${\mathit{I}}_{\mathit{c}}$${\mathit{R}}_{\mathit{n}}$) products of the junctions limited by the high specific contact resistance of the SN interfaces. The lowest values of the specific contact resistance obtained were on the order of ${10}^{\mathrm{\ensuremath{-}}8}$ \ensuremath{\Omega} ${\mathrm{cm}}^{2}$ for contacts in the c-axis direction. The specific contact resistance was measured as a function of deposition conditions for the Ag as well as annealing temperature and time. The influence of the specific contact resistance on the magnitude of the Josephson current in SNS bridges is discussed, and a review of the contact literature for noble-metal/YBCO contacts is presented.
Databáze: OpenAIRE