Conductivity behavior of La${}_{0.75}$Ca${}_{0.25}$MnO${}_3$ in vicinity of ferromagnetic-paramagnetic transition studied with single current pulses

Temperature and current dependences of resistivity of bulk La${}_{0.75}$Ca${}_{0.25}$MnO${}_3$ sample grown by the floating-zone method were studied using single ramp pulses of current. It is found that near the Curie temperature $T_C$ the sample resistance depends substantially on current magnitude. The observed features can be determined by inhomogeneous Joule overheating due to mixed phase state of manganites near the ferromagnetic-paramagnetic transition and percolation character of this transition.