Mechanochemically assisted synthesis of nanocrystalline BiFeO3

The synthesis of multiferroic BiFeO3 phase is carried out by means of a solid-state reaction induced by high energy ball-milling between metal chlorides (Lewis' acids) and sodium hydroxide (base). The chemical reaction occurs at room temperature and produces a solid mixture of nanocrystalline BiFeO3 and NaCl. Thermal treatments at several temperatures are performed to favor the crystallization of the desired phase. The evolution of the mechanochemical reaction and calcination are followed by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Electric and magnetic ordering transitions are determined by thermal analysis.

► The mechanochemical reaction of BiCl3, FeCl3 and NaOH yields BiFeO3 and NaCl.
► Heating at 600 °C improves the crystallization of the pure ferrite phase.
► NaCl byproduct is removed by washing of the calcined powder.
► BiFeO3 powder consists of particles of 100 nm formed by crystals of 30 nm.
► Magnetic and electric transitions are determined by thermal analyses.