Nonlinear conduction in charge-ordered Pr0.63Ca0.37MnO3: Effect of magnetic fields

Nonlinear conduction in a single crystal of charge-ordered Pr0.63Ca0.37MnO3 has bren investigated in an applied magnetic field. In zero held, the nonl inear conduction, which starts at T< T-CO, can give rise to a region of neg ative differential resistance (NDR) which shows up below the Neel temperatu re. Application of a magnetic held Inhibits the appearance of NDR and makes the nonlinear conduction strongly hysteritic on cycling of the bias curren t. This is most severe in the temperature range where the charge-ordered st ate melts in an applied magnetic field. Our experiment strongly suggests th at application of a magnetic field in the charge-ordering regime causes a c oexistence of two phases.