  This study reports on the synthesis of ball-like bismuth ferrite BiFeO3
nanoflowers by means of microwave assisted hydrothermal process and also on
their composition and mechanism of growth. It turns out that the petals of the
nanoflowers are composed of the nanocrystals with the size about 35-39 nm
whereas their thickness and size depends on the concentration of surfactants.
The petals contain BiFeO3 phase and traces of Bi2O3 oxide and metallic Bi and
Fe deposited mainly at their surface. Amounts of impurity phases are more
pronounced in nanoflowers synthesized during short time, and become almost
negligible for longer microwave processing. The nanoflowers contain also mixed
Fe valence, with the Fe2+/Fe3+ ratio depending on the time of synthesis. The
growth and shape of the nanoflowers result from the process of diffusion in the
initial stages of hydrothermal reaction.
