Emergence of large exchange anisotropy in Pr doped nanocrystalline spinel ferrites

This paper reports the influence of rare earth Pr3+ doping on microstructural and magnetic properties in soft nickel nanoferrites. All the samples were prepared by soft chemical co-precipitation route with the generic formula NiPrxFe2-xO4 (x = 0.00, 0.04, 0.08 and 0.12). The prepared nanoparticles were single-phase as verified by x-ray diffractograms. Mean crystallite sizes of all the samples were found in the range of 4 nm-15 nm from the Williamson-Hall plot. Raman spectra signalled the lowering of crystal symmetry of octahedral co-ordinated sites due to the doping of large size Pr3+ ions. Field cooled M(H) loops registered at 5 K detected the existence of significant exchange bias field and large coercivity in the samples. The superparamagnetic behavior of prepared nanoferrites at mom temperature became more prominent for higher Pr concentration as confirmed by both hysteresis loops and M(T) curves.

Automated summary

This paper discusses the impact of rare earth Pr3+ doping on the microstructural and magnetic properties of soft nickel nanoferrites. Higher Pr concentration intensifies the superparamagnetic behavior, leading to larger exchange bias fields and coercivity.