Dopant effects on the structural, optical and electromagnetic properties in multiferroic Bi1-xYxFeO3 ceramics
Multiferroic Bi1-xYxFeO3 (x = 0.00, 0.05, 0.1, 0.15, 0.2) ceramics were prepared by conventional solid-state-reaction method. X-ray diffraction measurement was carried out to characterize the crystal structure and to detect the impurities existing in these ceramics. The substitution of rare earth Y for Bi was found to decrease the impurity phase in BiFeO3 ceramics. There is strong evidence that both lattice constants a and c of the unit cell unusually change at Y content of about x = 0.10. The effect of introducing Y3+ is shown to increase the optical band gap for doped sample Bi1-xYxFeO3. Additionally, the Raman measurement performed for the lattice dynamics study of Bi 1-xYxFeO3 samples reveals a strong band centered at around 1150-1350 cm-1 which is associated with the resonant enhancement of two-phonon Raman scattering in the multiferroic Bi 1-xYxFeO3 samples. The impedance spectroscopy indicates that, the Y dopant has improved the grain impedance. The enhancement of magnetization was observed in Y-doped samples compared to pure BiFeO 3. © 2010 Elsevier B.V.All rights reserved.