Investigating the origin of exchange bias effect in ferromagnetic FeNi nanoparticles prepared via controlled synthesis

In the present work, FeNi nanoparticles have been synthesized using NaBH4 reduced co-precipitation technique followed by annealing at 210 °C for 4 h in a simple box furnace. The were characterized X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Energy-dispersive spectroscopy (EDS), Raman spectroscopy, and dc magnetization. XRD analysis revealed formation of dual phases (FeNi3; FeNi) with face-centred cubic symmetry along additional oxonium Ni oxide (NiOOH), hexagonal-Fe iron peroxide (FeOOH). FE-SEM micrographs demonstrated evolution dumb-bell shape morphology due to heterogeneous growth nuclei resulting into agglomeration particles. collectively confirmed nanometre (nm) dimensions mapping performed EDS spectra validates elemental compositions Nanoparticles. reiterated presence impurity addition trivial amount NiO. M–H (field dependent magnetization) hysteresis curves, plotted under conditions field cooled (FC) zero (ZFC), shifted horizontally ~ 14Oe indicating exchange bias. Alongside, FC-ZFC MT (temperature-dependent curves also showed bifurcation temperatures below 300 K that is an indicative brief, bias has ferromagnetic origin may be attributed interactions particle interfaces having canted spins which emerge impurities FeNi.