Preparation of high-quality BiFeO 3 nanopowders via a polyacrylamide gel route

Abstract

We report here an acrylamide gel route to prepare BiFeO 3 nanopowder. In this route, the gelation of the solution is achieved by the formation of a polymer network: the polyacrylamide, which provides a structural framework for the growth of particles. It is demonstrated that pure BiFeO 3 phase can be obtained using EDTA as the chelating agent. In addition, we find when the used acrylamide is 9 times the amount (in mole) of the cations and an appropriate amount of glucose is added to the precursor solution, the particle morphology can be much improved. SEM observations reveal that the powder prepared under the optimal conditions has a small and uniform particle size, and the particles are almost spherical and polydisperse without any agglomeration or adhesion. DSC measurements identify the presence of the two ferroic phase transitions in our product, i.e., the antiferromagnetic transition at ∼370 °C and the ferroelectric transition at ∼830 °C.