Journal of Advanced Dielectrics, Volume. 11, Issue 6, 2150027(2021)
Dielectric relaxation and scaling of AC conductivity observed in mixed valence perovskite Eu2CoMnO6
Md. G. Masud1、* and B. K. Chaudhuri2,3
Author Affiliations
1Department of Physics, Basanti Devi College, 147B Rash Behari Avenue, Kolkata 700 029, India2Center for Rural and Cryogenic Technologies, Jadavpur University, Kolkata 700 032, India3Formerly at Solid State Physics Department, Indian Association for the Cultivation of Science, Kolkata 700 032, India.show less
Monophasic and polycrystalline double perovskite Eu2CoMnO6 has been synthesized, and its structural characterization, frequency and temperature-dependent dielectric relaxation have been studied. Observed thermally activated dielectric relaxation was explained using the empirical Havriliak–Negami (HN) dielectric relaxation function with an estimated activation energy 0.22 eV and attempt frequency 2.46 × 109 Hz. The frequency-dependent AC conductivity data, over a wide range of temperature (100–325 K), followed the empirical universal power law behavior (, is the constant exponent) showing two different frequency exponents, respectively, in the high- and low-temperature regions. The high-temperature ( 275 K) conductivity data followed the continuous time random walk (CTRW) approximation model proposed by Dyre. However, this model failed to reproduce the observed conductivity spectra in the low-temperature side ( 200 K). Interestingly, both the high- and low-temperatures’ conductivity data can be scaled to the master curve with suitably chosen scaling parameters.Monophasic and polycrystalline double perovskite Eu2CoMnO6 has been synthesized, and its structural characterization, frequency and temperature-dependent dielectric relaxation have been studied. Observed thermally activated dielectric relaxation was explained using the empirical Havriliak–Negami (HN) dielectric relaxation function with an estimated activation energy 0.22 eV and attempt frequency 2.46 × 109 Hz. The frequency-dependent AC conductivity data, over a wide range of temperature (100–325 K), followed the empirical universal power law behavior (, is the constant exponent) showing two different frequency exponents, respectively, in the high- and low-temperature regions. The high-temperature ( 275 K) conductivity data followed the continuous time random walk (CTRW) approximation model proposed by Dyre. However, this model failed to reproduce the observed conductivity spectra in the low-temperature side ( 200 K). Interestingly, both the high- and low-temperatures’ conductivity data can be scaled to the master curve with suitably chosen scaling parameters.
