Enhancement of magnetoresistance in the intermediate state of Pr0.5Sr0.3Ca0.2MnO3

Current-voltage (I-V) characteristics of Pr0.5Sr0.3Ca0.2MnO3 are measured a t different temperatures and different fields. Our data of I-V curves show a crossover from linear to nonlinear behavior at the temperature lower than the charge ordering temperature. New findings in this work include (i) abr upt jumps/drops of voltage in each I-V curve below 100 K and (ii) an enhanc ement of magnetoresistance (MR) ratio from 15% to 20% which is associated w ith the unusual voltage jumps/drops in I-V curves. The enhancement of MR ra tio evidences the existence of an intermediate state between the charge ord ering state and the charge ordering breakdown state. Most importantly, the existence of such intermediate state provides a new route to achieve a low field colossal magnetoresistance for future applications of spintronics. (C ) 2001 American Institute of Physics.