MAGNETORESISTANCE FOR SINGLE-CRYSTALS OF BI2SR2CACU2OX IN PULSED HIGH MAGNETIC-FIELDS UP TO 40-T

The magnetoresistance along the c-axis of a single crystal of Bi2Sr2CaCu2Ox (Bi(2212)) was measured in pulsed high magnetic fields up to 40 T. The resistance increased steeply from zero with the application of a magnetic field below T(c)(B = 0), and became larger than the value just above T(c), as was reported previously. In the high field region, however, decrease of the resistance was observed. It is shown that this experimental fact, a kind of negative magnetoresistance in the high field region, can be explained by the contribution of the density of states term to the fluctuation conductivity.