The pinning influence on the Hall conductivity in the mixed state of high-temperature superconductors is still experimentally and theoretically controversial. In this work, the effect of twin-boundary pinning on the Hall conductivity is studied, with particular emphasis on the high-field results. The longitudinal and Hall resistivities were measured in YBa2Cu3O7-δand YbBa2Cu3O7-δ thin films, up to 18 T: a signature due to the pinning of the vortices in the twin boundaries is clearly visible in the longitudinal resistivity pxx and in the Hall resistivity pxy, but disappears when the Hall conductivity σxy≅pxy / p2xx is computed. However, at lower temperatures, a minimum of dσxy ldT is proved to be a weak signature of the twin-boundary pinning. These results are confirmed by similar measurements done on one sample rotated 16° away from the magnetic field direction.
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter And Materials Physics|
|Publication status||Published - 1 Sep 1997|