Synthesis and Properties of Bismuth Ferrite Multiferroic Nanoflowers

The method of microwave assisted hydrothermal synthesis of bismuth ferrite multiferroic nanoflowers, their mechanism of growth, magnetic as well as dielectric properties are presented. The nanoflowers are composed of numerous petals formed by BiFeO3 (BFO) nanocrystals and some amount of amorphous phase. The growth of the nanoflowers begins from the central part of calyx composed of only few petals towards which subsequent petals are successively attached. The nanoflowers exhibit enhanced magnetization due to size effect and lack of spin compensation in the spin cycloid. The dielectric properties of the nanoflowers are influenced by water confined to crystal nanovoids resulting in a broad dielectric permittivity maximum at 200 K {\div} 300 K and also by Polomska transition above the temperature of 450 K.