Effect of Y-doping on the electrical transport properties of nanocrystalline BiFeO3

Effect of yttrium doping on the electrical transport properties of sol-gel prepare nanocrystalline BiFeO3 was investigated. A comprehensive state-of-the art sophisticated instruments like x-ray diffraction, differential thermal analyzer, field emission scanning electron microscope, and HRTEM were utilized to characterize the BiFeO3 nanoparticles. It was observed that the values of dc activation energy calculated from Arrhenius relation increase with increase of yttrium content. The variation of ac conductivity with frequency and temperature exhibits a correlated barrier hopping conduction mechanism. The dielectric permittivity of the sample reveals an increasing tendency with the concentration of yttrium and depends on both the grain and the interfacial grain boundary resistance. The activation energies for the dielectric relaxation estimated from the modulus spectra were found to be reasonably good agreement with those obtained from dc conductivity study. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4734005]