Non-overlapping small polaron and overlapping large polaron assisted conduction relaxation in polycrystalline YFe0.9Cr0.1O3-An impedance spectroscopic and AC conductivity studies

Detailed ac electrical investigations within the frequency range 100 Hz-1 MHz have been conducted on the polycrystalline YFe0.9Cr0.1O3 samples prepared via solid state reaction route, in a broad thermal interval of 298-673 K. A systematic development of grain, grain boundary and electrode polarization contribution have been observed with increasing temperature. The thermal variation of the grain resistance (R g) and grain boundary resistances (R gb) followed the non-adiabatic small polaron hopping (SPH) model and is responsible for the long-range conduction with different values of the activation energies at different thermal regimes. The ac conductivity of the material exhibited series of dispersive regions with broad region, where the slope changes occurred up to 473 K. Above 473 K, appreciable dc conductivity in the material can be seen. Different dispersive regions in the conductivity spectrum obeyed single power law and power law variation (A omega n).

Automated summary

Detailed ac electrical investigations were conducted on polycrystalline YFe0.9Cr0.1O3 samples prepared via solid state reaction route within the frequency range 100 Hz-1 MHz, at a broad thermal interval of 298-673 K. The research observed systematic development of grain, grain boundary, and electrode polarization contribution with increasing temperature. The thermal variation of the grain resistance and grain boundary resistances followed the non-adiabatic small polaron hopping model and contributed to long-range conduction with different activation energies at different thermal regimes. The ac conductivity exhibited series of dispersive regions with broad region below 473 K, and significant dc conductivity was observed above 473 K. Different dispersive regions in the conductivity spectrum followed single power law and power law variation (A omega n).