The complex dielectric constant/ac electrical conductivity was investigated as a function offrequency and temperature in Pb_(5)Cr_(3)F_(19).The system undergoes a ferroelectric phase transition at higher temperatures....The complex dielectric constant/ac electrical conductivity was investigated as a function offrequency and temperature in Pb_(5)Cr_(3)F_(19).The system undergoes a ferroelectric phase transition at higher temperatures.At lower temperatures the real part of the complex ac electric conductivity was found to follow the universal dielectric response(UDR)σ′∝v^(s),typical for hopping or tunneling of localized charge carriers.A detailed analysis of the temperature dependence of the UDR parameter s in terms of the theoretical model for tunneling of small polarons revealed that,at low temperatures,this mechanism governs the charge transport in Pb_(5)Cr_(3)F_(19).The value of the inverse attempt frequency τ0 indicates the femtosecond tunneling of polarons in the system similar to the Büttiker-Landauer transversal time.展开更多
基金Research was supported by the Slovenian Research Agency(P1-0125).
文摘The complex dielectric constant/ac electrical conductivity was investigated as a function offrequency and temperature in Pb_(5)Cr_(3)F_(19).The system undergoes a ferroelectric phase transition at higher temperatures.At lower temperatures the real part of the complex ac electric conductivity was found to follow the universal dielectric response(UDR)σ′∝v^(s),typical for hopping or tunneling of localized charge carriers.A detailed analysis of the temperature dependence of the UDR parameter s in terms of the theoretical model for tunneling of small polarons revealed that,at low temperatures,this mechanism governs the charge transport in Pb_(5)Cr_(3)F_(19).The value of the inverse attempt frequency τ0 indicates the femtosecond tunneling of polarons in the system similar to the Büttiker-Landauer transversal time.
