Study of electrical and magnetic properties of Pr0.6−xBixSr0.4MnO3 (x=0.20 and 0.25)

We have investigated the electrical and magnetic properties of Pr0.6-xBixSr0.4MnO3 (x=0.20 and 0.25) manganites. XRD data shows that the synthesized samples are single-phase and crystallize in the orthorhombic structure with Pnma space group. Resistivity measurements show that the sample with x=0.25 exhibits a thermally activated behavior for the entire temperature range. The magnetoresistance (MR) for the x=0.25 sample is as high as nearly 100% over a wide range of temperature, demonstrating its important technological application as a material for MR-based devices. From the magnetization measurements, two magnetic transitions viz. paramagnetic insulating to ferromagnetic metallic (PMI-FMM) transition at TC and the ferromagnetic metallic (FMM) to antiferromagnetic insulating (AFI) transition at Neel temperature TN were observe in both samples. The Curie temperature decreases with bismuth doping, while TN increases with Bi content. Most interestingly, the temperature variation of magnetization and resistivity shows hysteresis behavior across the transition for the x=0.20 sample.