AC CONDUCTIVITY AND DIELECTRIC PROPERTIES OF MANGANESE DOPED LAYERED Na1.89Li0.10K0.01Ti3O7 CERAMICS

Abstract

Manganese doped derivatives of polycrystalline Na 1.89 Li 0.10 K 0.01 Ti 3 O 7 bearing 0.01, 0.05 and 1.0 molar % of manganese have been prepared by chemical synthesis. The results of ac electrical conductivity studies in form of log (σT) versus 1000/T plots are reported in the frequency and temperature range of 10 kHz–1 MHz and 350–775 K, respectively. The corresponding plots have been divided into five temperature regions, I, II, III, IV and V. The various conduction mechanisms in different regions have been discussed. The nature of conductivity has been explained by proposing a model about the obtained conductivity σ(ω) which is the sum of three terms arising from three different mechanisms. Moreover, various Na–K–Li–O–Ti–O linkages in Na 2-x-y Li x K y Ti 3 O 7 materials may result special forms of electron clouds. Experimental results of the loss tangent ( tan δ) and relative permittivity (εr) versus temperature at different frequencies have been described. The results of tan δ and εr versus frequency plots at different temperature have also been given for these doped derivatives.