Thermopower and Hall conductivity in the magnetic-field-driven normal state of Pr2-xCexCuO(4-delta) superconductors

Measurements of thermoelectric power (TEP) and Hall coefficient (R-H) are carried out on Pr2-xCexCuO4-delta epitaxial films to probe the mechanism of charge transport in the absence of superconductivity. In the under-doped (x=0.13) and optimally doped (x=0.15) samples, the TEP shows a ln(1/T) dependence and the R-H remains constant in the temperature range accessed by suppressing superconductivity. These observations and the behavior of the in-plane resistivity indicate weak localization of charge carriers on the CuO2 planes. The TEP and R-H of the overdoped sample mimic metallic transport. This, combined with the evidence for hole and electron charge carriers, which may exist on different planes of the unit cell, suggests that the metallic transport in the overdoped samples is a consequence of a three-dimensional charge distribution.