Ac conductivity study of lithium and potassium diphosphate LiK3P2O7 using impedance spectroscopy

作者：Zaafouri Amira^*; Megdiche Makram; Mechi Lassad; Gargouri Mohamed

来源：Ionics, 2014, 20(9): 1255-1266.

DOI：10.1007/s11581-014-1086-3

• Pyrophosphate
• Impedance spectroscopy
• Dielectric properties
• Electrical conductivity
• Thermodynamic

In this work, a LiK3P2O7 ceramic material was prepared by the solid-state reaction method and identified by X-ray diffractometry. The dielectric properties, impedance characteristics, and modulus were studied over a range of frequency (200 Hz to 5 MHz) and temperature (615-708 K). The frequency and temperature dependence of dielectric permittivity, dielectric loss, and electric modulus is studied. The frequency analysis of modulus properties showed a distribution of relaxation times. Conductivity plots against frequency at a higher frequency suggested the response obeying the universal power law. The temperature behavior of the frequency exponents shows that the correlated barrier hopping CBH model is well adapted to this material. The activation energy associated with the impedance relaxation and the electric modulus spectra is close to the activation energy for dc conductivity indicating the similar nature of relaxation and conductivity. Thermodynamic parameters such as free energy of activation, enthalpy, and entropy have been calculated.

• 出版日期2014-9