Electrical Conductivity in Ba5RTi3-xZrxNb7O30 [R = La or Dy] Ceramics

Abstract

The polycrystalline samples of Ba₅RTi₃__xZr_xNb₇O₃₀ [R = La or Dy;
x = 0, 1,2,3] belonging to tungsten-bronze (TB) structural family were
prepared by using conventional high-temperature solid-state reaction technique.
Studies of electrical conductivity/resistivity as a function of biasing
electrical field and a wide range of temperature have been carried out. The
activation energy (E_a) of the compounds was calculated from the plot of
dc resistivity and ac conductivity vs. absolute temperature. Dc resistivity
studies show that the increase of Zr concentration enhances the resistivity
characteristics of Ba₅DyTi₃ _ _xZr _xNb₇O₃₀ and decreases the resistivity
characterisities of Ba₅LaTi₃ _ _xZr_xNb₇O₃₀ compounds. The compounds exhibit
the negative temperature coefficient of resistance (NTCR) properties
at higher temperature region.