Ferroelectric and dielectric properties of Mn doped BiFeO_3 bulk ceramics

摘要

The structural, dielectric and ferroelectric properties of BiFeO_3 and BiMnxFe_(1-x)O_3 with x = 0.03 samples synthesized by the conventional solid state reaction method has been studied. The XRD pattern clearly shows the suppression of impurity phases with the substitution of Mn at Fe - site. Dielectric properties of the samples in frequency range 4 Hz - 1 MHz has been measured at room temperature. A strong dispersion was observed in the dielectric constant at low frequencies due to Maxwell-Wagner type of interfacial polarization. At higher frequencies, dielectric constant shows frequency independent behavior indicating an intrinsic dielectric response. The BiMn_(0.03)Fe_(0.97)O_3 sample exhibit loosy and unsaturated ferroelectric loop at room temperature due to the presence of oxygen vacancies.