Journal of Low Temperature Physics vol:163 issue:3-4 pages:176-183
A conduction mechanism has been investigated in the phase-separated compound (La0.73Bi0.27)(0.67)Ca0.33MnO3 at various temperatures below and above the ferromagnetic-paramagnetic (FM-PM) transition temperature T (c) . When a high current density applied, a strong nonlinear behavior with negative differential resistance (NDR) was observed. The application of an external magnetic field inhibits the appearance of NDR. Usually, the experiments strongly suggest that the electric field has an important effect on the nonlinear conduction behavior of the sample. However, our experiment shows that, instead of the electric field effect (that is electroresistance), the observed nonlinear behavior results mainly from the Joule heating effect. Thus, we should exercise extreme caution when interpreting the nonlinear conduction behavior of the phase-separated system.