Electrical Properties of Undoped and Lanthanum Doped BaTi0.6Zr0.4O3

Lanthanum doped BaTi_0.6Zr_0.4O₃ composition x = 0.005, 0.01, 0.02, 0.05 and 0.1 in Ba_1-xLa_xTi_0.6[1-5x/12]Zr_0.4O₃ were prepared by modified chemical route. (COOH)₂ldr2H₂O, Ba(NO₃)₂, ZrOCl₂ldr8H₂O and La₂O₃ are used to precipitate barium oxalate hydrate, lanthanum oxalate hydrate and zirconium oxy-hydroxide from its water solution onto the surface of suspended TiO₂ particles. The lanthanum doped BaTi_0.6Zr_0.4O₃ composition was found to be cubic by XRD analysis. A gradual shift of 2thetas angles to the higher angle with increasing lanthanum percentage in the BTZ reveals the contraction of perovskite lattice. The frequency dependence of dielectric permittivity and loss tan delta of the ceramics has been investigated. It is found that dielectric permittivity (epsiv_tau) decreases and loss tan delta decreases with increase in lanthanum percentage. Neither of the samples shows semiconductivity, which is believed to be because of titanium vacancy compensation.