Perovskite-type RCoO3 (R = Pr, Eu, Gd) nanofibers for supercapacitor electrodes and antiferromagnet

Rare earth orthocobaltates nanofibers (PrCoO 3 , EuCoO 3 , and GdCoO 3 ) were prepared by a simple electrospinning method coupled with calcination. The PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers have orthorhombic perovskite structure. The fabricated electrodes presented the typical pseudocapacitive characteristics, which originated from the reversible redox reactions of Co 2+ /Co 3+ and Fe(CN) 6 3− /Fe(CN) 6 4− . At 1 A g −1 , the specific capacitances of the PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers were 119, 133, and 196 F g −1 , respectively. The electrochemical characteristics of the PrCoO 3 , EuCoO 3 , and GdCoO 3 nanofibers exhibited favorable specific capacitance, good long-term cycling stability, and high coulombic efficiency, proving the possible application into energy storage devices. PrCoO 3 and EuCoO 3 nanofibers exhibited a magnetic state transition from paramagnetic to antiferromagnetic state. GdCoO 3 nanofibers showed a paramagnetic ordering at high temperature. The cooperation of the R 3+ ions and the Co 2+ ions contributed to the magnetism of rare earth orthocobaltates nanofibers. The antiferromagnetic behaviors of the fabricated samples confirm the potential application into spin-electronic devices.