Preparation of PSFO and LPSFO nanofibers by electrospinning and their electronic transport and magnetic properties

Pr_0.5Sr_0.5FeO₃ (PSFO) and La_0.25Pr_0.25Sr_0.5FeO₃ (LPSFO) nanofibers are prepared by electrospinning followed by calcination, and their morphologies, microstructures, electronic transports, and magnetic properties are studied systematically. The temperature-dependent resistance curves of PSFO and LPSFO nanofibers are measured in a temperature range from 300 K to 10 K. With the temperature lowering, the resistance increases gradually and then decreases sharply due to the occurrence of ferromagnetic metal phase. The metal-insulator transition temperatures are about 110 K and 180 K for PSFO and LPSFO nanofibers, respectively. The electronic conduction behavior above the transition temperature can be described by one-dimensional Mott's variable-range hopping (VRH) model. The hysteresis loops and the field-cooled (FC) and zero-field-cooled (ZFC) curves show that both PSFO nanofiber and LPSFO nanofiber exhibit ferromagnetism. Although the doping of La reduces the overall magnetization intensity of the material, it increases the ferromagnetic ratio of the system, which may improve the performance of LPSFO in solid oxide fuel cell.