Synthesis and properties of bismuth ferrite multiferroic flowers

Novel, flowerlike bismuth ferrite BiFeO3 (BFO) multiferroic structures were prepared for the first time by means of microwave assisted hydrothermal synthesis. The flowers are composed of numerous petals formed by BFO nanocrystals and some amount of amorphous phase. The growth of the flowers begins from the central part of calyx composed of only few petals toward which subsequent petals are successively attached. The flowers exhibit enhanced magnetization due to size effect and lack of spin compensation in the spin cycloid. The dielectric properties of the flowers are influenced by BFO amorphous phase resulting in a broad dielectric permittivity maximum at 200-300 K and also by Polomska transition due to anomalous surface magnon damping above the temperature of 450 K. Possible applications of BFO flowerlike structures assume optoelectronic devices, excellent field emitters, effective solar cells, or catalyst supports.