Tuning photocatalytic activity and magnetic behavior of Bi0.8Re0.2FeO3(Re = Nd, Sm) multiferroics

For the investigation of the exchange bias effect and magneto-optical properties of Bi0.8Re0.2(Re = Nd and Sm)FeO3 (BNFO and BSFO) nanofibers were synthesized via the electrospinning technique. The crystal structure was changed from rhombohedral phases of space group R3c before undoping shift to orthorhombic phases of space group Pbam and Pnma after doping of Nd3+ and Sm3+ ions, respectively, by the Rietveld refinement results. Analysis of the magnetic hysteresis loops demonstrated that the remanent magnetization especially coercivity of BNFO and BSFO nanofibers at 10 K and 300 K exhibited obviously variation, which was attributed to the lower temperature suppressed the fluctuation of magneto-caloric and valence state. The XPS and EDS results displayed the Nd3+ and Sm3+ ions were successfully doped into BFO nanofibers. Meanwhile, the lattice distortion induced the suppression of antiferromagnetic ordered spin modulation, which played an important role to enhance the magnetic properties. It was observed that the exchange bias effect (HEB) of BNFO nanofibers was higher than those of BSFO nanofibers. UV–vis spectra measurements revealed the band gap of BNFO and BSFO nanofibers was 1.87 eV and 1.85 eV, respectively, and the absorption edges of BSFO nanofibers occurred a slightly red shift. The MO degradation rates of BNFO and BSFO nanofibers reached about 89.4% and 78.6%, respectively, which could be a potential candidate in photo-electron devices and the semiconductor industry.