Impedance analysis of Pb_2Sb_3LaTi_5O_(18) ceramic

摘要

Polycrystalline sample of Pb_2Sb_3LaTi_5O_(18), a member of tungsten-bronze (TB) family, was prepared using a high temperature solid-state reaction technique. XRD analysis indicated the formation of a single-phase orthorhombie structure. The dielectric studies revealed the diffuse phase transition and the transition temperature was found to be at 52 deg C. Impedance plots were used as tools to analyse the sample behaviour as a function of frequency. Cole-Cole plots showed Debye relaxation. The activation energy was estimated to be 0.634 eV from the temperature variation of d.c. conductivity. The nature of variation of d.c, conductivity with temperature suggested NTCR behaviour.