Monophasic and polycrystalline double perovskite Eu_(2)CoMnO_(6)has been synthesized,and its structural characterization,fre-quency and temperature-dependent dielectric relaxation have been studied.Observed thermally ...Monophasic and polycrystalline double perovskite Eu_(2)CoMnO_(6)has been synthesized,and its structural characterization,fre-quency 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 E~0.22 eV and attempt frequency f0~2.46×10^(9)Hz.The frequency-dependent AC conductivity data,over a wide range of tempera-ture(100-325 K),followed the empirical universal power law behavior(~f n,n 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 repro-duce 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.展开更多
文摘Monophasic and polycrystalline double perovskite Eu_(2)CoMnO_(6)has been synthesized,and its structural characterization,fre-quency 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 E~0.22 eV and attempt frequency f0~2.46×10^(9)Hz.The frequency-dependent AC conductivity data,over a wide range of tempera-ture(100-325 K),followed the empirical universal power law behavior(~f n,n 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 repro-duce 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.
