Giant dielectric response and magnetoelectric behavior of 95BiFeO₃–5BaTiO₃ (95BFO–5BT) ceramics

A detailed study of electrical behavior of 95BiFeO₃–5BaTiO₃ (95BFO–5BT) ceramics through comprehensive analysis of temperature and frequency dependent dielectric behavior, ac impedance and magnetodielectric (MD) properties is reported here. Addition of insulating BaTiO₃ into BiFeO₃ have exhibited enhanced dielectric and ferromagnetic responses. The remnant polarization (P_r) was found to be 6 µC/cm², while the dielectric constant was found to be very high (\(\varepsilon_{\text{r}}^{\prime }\) ≥ 10², for T ≥ 140 °C). Along with strong conductivity contribution to \(\varepsilon_{\text{r}}^{\prime }\), spectroscopic plots of \(\varepsilon_{\text{r}}^{\prime }\) revealed the Maxwell–Wagner type relaxation in the sample, which ultimately could have led to an apparent high \(\varepsilon_{\text{r}}^{\prime }\) in 95BFO–5BT ceramics. Origin of such a high \(\varepsilon_{\text{r}}^{\prime }\) in BFO–BT was further investigated using impedance spectroscopy. MD studies revealed the magneto-electric coupling in the ceramics. The MD studies along with anomaly in dielectric data near antiferromagnetic ordering temperature (T_N = 170 °C) of BFO suggests the magnetic bearing on the electrical properties of 95BFO–5BT ceramics.