Charge-transfer-driven enhanced room-temperature ferromagnetism in BiFeO₃/Ag nanocomposite

We report observation of more than an order of magnitude jump in saturation magnetization in BiFeO3/Ag nanocomposite at room temperature compared to what is observed in bare BiFeO3 nanoparticles. Using transmission electron microscopy together with energy dispersive x-ray spectra (which maps the element concentration across the BiFeO3/Ag interface) and x-ray photoelectron spectroscopy, we show that both the observed specific self-assembly pattern of BiFeO3 and Ag nanoparticles and the charge transfer between Ag and O are responsible for such an enormous rise in room-temperature magnetization. The BiFeO3/Ag nanocomposites, therefore, could prove to be extremely useful for a variety of applications including biomedical.