High-Temperature Resistivity Measurements of YBa2Cu3O7-x

Abstract
The high-temperature resistivity of YBa2Cu3O7-x was measured by a DC four-probe technique at partial oxygen pressures (p O2 ) of 1.0, 0.2, 0.053, 0.013 and 0.006 atm. The determined resistivity values increased with increasing temperature and decreasing p O2 in accordance with the increase of the oxygen deficiency. The discontinuous change of the slopes d(log ρ)/d(1/T) was observed at temperatures 20–95°C lower than those reported for the orthorhombic-to-tetragonal transition.