10 research outputs found
Sign reversal of the Hall resistance in the mixed-state of La CeCuO and LaCe(CuCo)O thin films
The transport properties of LaCeCuO(LCCO) and
LaCe(CuCo)O (LCCO:Co) superconducting
thin films are investigated. When the external field is applied along
the crystallographic c-axis, a double sign reversal of the Hall voltage in the
mixed state of LCCO:Co thin films is observed whereas a single sign reversal is
detected in LCCO. A double sign reversal of the Hall signal in LCCO can be
recovered if the magnetic field is tilted away from the plane of the film. We
find that the transition from one to two of the Hall sign reversal coincides
with the change in the pinning from strong to weak. This temperature/field
induced transition is caused either by the magnetic impurities in LCCO:Co or by
the coupling between the pancake vortices and the in-plane Josephson vortices
in LCCO. These results are in agreement with early theoretical and numerical
predictions.Comment: 6 pages, 4 figures, the proceedings of VORTEX VII in Physica