Magnetic and electric transport properties of polycrystalline manganite Pr0.6Na0.4MnO3

The magnetic and electric transport properties of the polycrystalline manganite Pr0.6Na0.4MnO3 were reported. In zero field, the sample shows an insulator behavior. Under applied fields higher than 10 kOe, a field-induced insulator-metal transition occurs, and at the same time the colossal magnetoresistance (CMR) effect is also observed. At the temperature of 5 K, the metamagnetic transition from charge ordering/antiferromagnetic (CO/AFM) to ferromagnetic (FM) state is observed. With increasing temperature, the metastable FM phases can transform back to the CO state, accompanied by a high field hysteresis. The CMR effect of the sample can be understood by a percolative regime and is related to the CO-FM transition under a large magnetic field.