Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1515236 | Journal of Physics and Chemistry of Solids | 2016 | 8 Pages |
Abstract
Erbium substituted cobalt ferrite (CoFe2âxErxO4; x=0.0-0.2, referred to CFEO) materials were synthesized by sol-gel auto-combustion method. The effect of erbium (Er3+) substitution on the crystal structure, dielectric, electrical transport and magnetic properties of cobalt ferrite is evaluated. CoFe2âxErxO4 ceramics exhibit the spinel cubic structure without any impurity phase for xâ¤0.10 whereas formation of the ErFeO3 orthoferrite secondary phase was observed for xâ¥0.15. All the CFEO samples demonstrate the typical hysteresis (M-H) behavior with a decrease in magnetization as a function of Er content due to weak superexchange interaction. The frequency (f) dependent dielectric constant (εâ²) revealed the usual dielectric dispersion. The εâ²-f dispersion (f=20 Hz to 1 MHz) fits to the modified Debye's function with more than one ion contributing to the relaxation. The relaxation time and spread factor derived are â¼10â4 s and â¼0.61(±0.04), respectively. Electrical and dielectric studies indicate that εⲠincreases and the dc electrical resistivity decreases as a function of Er content (xâ¤0.15). Complex impedance analyses confirm only the grain interior contribution to the conduction process. Temperature dependent electrical transport and room temperature ac conductivity (Ïac) analyses indicate the semiconducting nature and small polaron hopping.
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Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
S.G. Kakade, R.C. Kambale, Y.D. Kolekar, C.V. Ramana,