We have investigated the normal-state resistance and the excess low-frequency (1/f) noise in 45°tilt  grain-boundary junctions in YBa2Cu3O7 thin films. A characteristic temperature dependence of the resistance fluctuations and a linear temperature dependence of the grain-boundary resistance (with a negative temperature coefficient) emerge as common features. These observations are quantitatively compared with a model of many, parallel conduction paths across the boundary, taking into account both temperature-independent and thermally activated transport processes.
ASJC Scopus subject areas
- Condensed Matter Physics