HALL EFFECT AND MAGNETORESISTANCE IN ND(1.8)5CE(0.15)CUO(4-DELTA) FILMS

The electrical transport properties af the cuprate superconductor Nd1. 85Ce0.15CuO4-delta have been studied in the mixed state and in the nor mal conducting state by measuring the Hall voltage and the longitudina l voltage of an epitaxial thin film. A broadening of the resistive tra nsition with increasing fixed magnetic field and a sign reversal of th e Hall effect in the mixed state were observed. In the normal state, t he zero-field resistivity shows a quadratic temperature dependence. Ma gnetoresistance measurements for T = 102 and 55 K yield a B-2 dependen ce up to B = 10 T without any saturation tendency. The normal-state Ha ll coefficient is temperature dependent with a sign change from negati ve to positive for decreasing temperature. The data can be interpreted within a two-band model.