Insights into the conduction mechanism of magneto-dielectric BaFe10.5In1.5O19: an impedance spectroscopy and AC conductivity study

Impedance spectroscopy and ac conductivity analysis as a function of temperature have been employed to investigate the conduction mechanism in indium-doped M-type barium hexaferrite (BaFe10.5In1.5O19). Impedance spectra revealed the temperature dependence of dielectric relaxation. The grain and grain boundary contributions to the dielectric properties have been deconvoluted by modeling the Nyquist plot (Z '' vs. Z ') with an equivalent electrical circuit. The ac conductivity was found to follow Jonscher's power law and the temperature-dependent behavior of critical exponent (s) substantiated the presence of overlapping large polaron tunneling (OLPT) as the underlying conduction mechanism in the investigated temperature regime.

Automated summary

Impedance spectroscopy and ac conductivity analysis were used to investigate the conduction mechanism in indium-doped M-type barium hexaferrite as a function of temperature. The temperature dependence of dielectric relaxation was revealed by impedance spectra. The contributions of grain and grain boundaries to dielectric properties were deconvoluted using an equivalent electrical circuit. The ac conductivity followed Jonscher's power law and the temperature-dependent behavior of the critical exponent indicated the presence of overlapping large polaron tunneling as the underlying conduction mechanism.