News & Event

There is a continuously growing interest in developing and investigating hetero-nanostructures with tailored magnetic properties owing to their various technological and biomedical applications, such as magnetic recording media, sensors, hyperthermia, drug delivery system, and magnetic contrast agent. One of the most exciting phenomena encountered in the bi-magnetic nanostructures is the so-called Exchange Bias Effect, which is manifested by a horizontal shift of the magnetic hysteresis loop when cooled in the presence of a magnetic field below the ordering temperature. Here, we present a substantial enhancement of the coercive field and huge exchange bias effect under the field-cooled condition of the bi-magnetic hybrid nanostructures containing the nanoscale Fe₃O₄ and NiO phases prepared by a hydrothermal one-pot synthesis method. The detailed microstructural characterization also supports the proximity effect of the two magnetic phases, suggesting strong interfacial coupling. Our first-principle density functional theory calculations indicate an increase in the anisotropy of the interface layer, which may arise due to the cation mixing at the interfacial layer.