Enhanced magnetization in Dy-doped Bismuth ferrite nanoparticles

Multiferroic nanoparticles of Bi1-xDyxFeO3 (x=0 and 0.10) have been prepared by sol-gel method and the variation in their structural, morphological and magnetic properties has been studied. Structural analysis reveals distortion of rhombohedral lattice of BiFeO3 by the substitution of Dy3+ions. The shift observed in the diffraction peaks with Dy3+ ions indicates its successful substitution. The morphological analysis shows the formation of agglomerated nanoparticles having average particle size 25 and 18 nm for undoped and Dy-doped BiFeO3 nanoparticles, respectively. The observed agglomeration is due to high surface energy of synthesized nanoparticles. Magnetic studies confirm typical ferromagnetic behavior for the synthesized nanoparticles. Enhancement in saturation magnetization values with Dy-substitution is attributed to suppression of spin cycloid structure by the reduction in particle size, lattice distortion and surface induced magnetization.