Temperature Dependent Magnetic, Dielectric Studies of Sm-Substituted Bulk BiFeO3

Abstract

Bismuth ferrite- (BiFeO3) ceramic is the most studied and attractive multiferroic material with low magnetization, moderate leakage current, and low polarization. Samarium substituted bulk BiFeO3 prepared at low synthesis temperature ∼600 °C by the sol–gel process. Room temperature X-ray diffraction (XRD) patterns confirmed the formation of perovskite structure Bi0.9Sm0.10FeO3 (BSFO) phases. Present compositions possess high dielectric constant (e≈199) and low dielectric loss (tanδ≈0.009) at room temperature for 100 Hz frequency. Room temperature dielectric permittivity and dielectric loss decreased with increasing frequency from 100 Hz to 10 MHz. As the temperature increased, an enormous increase in both dielectric permittivity and dielectric loss is observed at all frequency regions. Temperature dependent M–H hysteresis loops were saturated. Spin glass-like ferromagnetic behavior is retained in M–H hysteresis loops measured from the low temperature region and normal ferromagnetic behavior is observed in the high temperature region, both at room temperature and above ∼350 K, 400 K, respectively. The origin of the ferromagnetic property in BSFO may be due to the presence of rare earth metal ions at the lattice sites of BFO.