High-field magnetoresistance and Hall effect in Bi2Sr2CuO x single crystals

Abstract

We investigated the in-plane magnetoresistance and the Hall effect of high-quality Bi2Sr2CuOx single crystals with T c (midpoint) = 3.7–9.6 K in dc magnetic fields up to 23 T. For T < 10 K, the crystals show the classical positive magnetoresistance. Starting at T ≈ 14 K, an anomalous negative magnetoresistance appears at low magnetic fields; for T ≥ 40 K, the magnetoresistance is negative in the whole studied range of magnetic fields. Temperature and magnetic field dependences of the negative-magnetoresistance single crystals are qualitatively consistent with the electron interaction theory developed for simple semiconductors and disordered metals. As is observed in other cuprate superconductors, the Hall resistivity is negative in the mixed state and changes its sign with increasing field. The linear T-dependence of cotθH for the Hall angle in the normal state closely resembles that of the normal-state resistivity as expected for a Fermi liquid picture.