Study of complex impedance spectroscopic properties of LiBa2Nb5O15 ceramics

The polycrystalline sample of LiBa2Nb5O15 (LBN) was prepared by a high-temperature solid-state reaction technique. The effect of temperature on impedance parameters was studied using an impedance analyzer in a wide frequency range (102–106 Hz) at different temperatures. The real and imaginary part of complex impedance traces semicircle(s) in the complex plane. The temperature dependent plots reveal the presence of both bulk and grain boundary effects above 125 °C. The bulk resistance of the material decreases with rise in temperature. This exhibits a typical negative temperature coefficient of resistance (NTCR) behavior of the material. The ac conductivity spectrum obeys Jonscher's universal power law. The modulus analysis suggests a possible hopping mechanism for electrical transport processes of the material. The nature of variation of dc conductivity suggests Arrhenius type of electrical conductivity.