Dielectric and ferroelectric properties of CoCr2O4 nanoceramics

CoCr2O4 nanoceramics are prepared by sol–gel auto combustion method. Synchrotron X-ray diffraction analysis affirms the single-phase pristine cubic structure with space group Fd3m. Debye–Scherrer method estimates the crystallite size of main intense peak to be ∼27.15nm. Prominent bands obtained in i...

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Bibliographic Details
Main Authors: Pankaj Choudhary, P. Saxena, A. Yadav, V. N. Rai, A. Mishra
Format: Article
Language:English
Published: World Scientific Publishing 2019-06-01
Series:Journal of Advanced Dielectrics
Subjects:
Online Access:http://www.worldscientific.com/doi/pdf/10.1142/S2010135X19500152
Description
Summary:CoCr2O4 nanoceramics are prepared by sol–gel auto combustion method. Synchrotron X-ray diffraction analysis affirms the single-phase pristine cubic structure with space group Fd3m. Debye–Scherrer method estimates the crystallite size of main intense peak to be ∼27.15nm. Prominent bands obtained in infrared spectra at 448 and 599cm−1 are due to metal–oxygen stretching bond present at tetrahedral and octahedral sites. Dielectric parameters decrease as frequency increases from 103 to 106Hz that can be interpreted by Maxwell–Wagner-type interfacial polarization. Complex impedance spectra (Nyquist plot) reveal arc like behavior, which is mainly due to intergrain (grain boundary) resistance that also exhibits conducting nature of the nanoceramics. Weak ferroelectricity is mainly associated with the partial reversal of the polarization. Leakage current behavior follows the Ohmic and Child square law. Electron conduction process was interpreted by space-charge limited current (SCLC) mechanism. Leakage current behavior observed in cobalt chromite nanoceramics is mainly attributed to the oxygen vacancies.
ISSN:2010-135X
2010-1368