Electrical transport properties of manganese containing pyrochlore type semiconducting oxides using impedance analyses

Sumi, S.; Rao, P. Prabhakar; Mahesh, Sankarapillai; Koshy, Peter

doi:10.1016/j.materresbull.2012.09.034

Cited by 19 publications

(1 citation statement)

References 42 publications

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“…As concerns the frequency-independent part, the Z' behavior can be explained by pure resistance of the grains. For the frequency-dependent part, however, the resistance and capacitance of the grains contribute simultaneously to the observed response [22].…”

Section: Impedance Spectroscopy Analysesmentioning

confidence: 98%

Dielectric properties of calcium-substituted lanthanum ferrite

Andoulsi-Fezei

Sdiri

Horchani−Naifer

et al. 2020

Journal of Asian Ceramic Societies

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Among La 1-x Ca x FeO 3-δ (0 ≤ x ≤ 0.5) compounds, the optimal value of the direct current conductivity was registered for a 20% substituted amount. We therefore attempted to study the impedance and dielectric properties of 20% calcium-substituted lanthanum ferrite. We investigated the electric properties in depth between 5 Hz and 13 MHz from 350 to 800°C. The results reveal interesting properties. Indeed, the perovskite shows a huge dielectric constant which promotes its utilization in high-performance dielectric material applications. At a given temperature, ε' and tan(δ) decrease with increases in frequency. This trend was explained based on the Maxwell Wagner polarization model. The variations in dielectric loss (ε") with frequency obey the Giuntini theory based on the hopping model. As the temperature increases from 350 to 800°C, the binding energy increases from 0.22 to 0.34 eV, while the minimum hopping distance decreases from 2.16 to 0.12 pm. Consideration of the electric modulus analyzes showed that the relaxation mechanism is dominated at below 400°C by a shortrange movement of charge carriers, whereas at above that temperature, a long-range movement of charge carriers is dominant. This study presents a solid foundation for the polarization and dielectric properties of lanthanum ferrite, which is a lead-free, environmentally friendly material and a promising candidate for use in nonlinear optical applications and microwave devices.

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Section: Impedance Spectroscopy Analysesmentioning

confidence: 98%