Effect of La-substitution on structural and dielectric properties of Bi(Sc1/2Fe1/2)O3 ceramics

The polycrystalline samples of La-modified Bi(Sc1/2Fe1/2)O-3 (i.e., (Bi1-xLax)(Sc1/2Fe1/2)O-3) were prepared using a solid-state reaction technique. The formation of single-phase compound was checked with an X-ray diffraction (XRD) technique. A small amount of La-substitution (0 <= x <= 0.15) at the Bi site does not change the crystal structure of Bi(Sc1/2Fe1/2)O-3. Detailed studies of dielectric properties (i.e., dielectric constant, loss tangent and ac conductivity) showed significant effect of La doping on these properties. High dielectric constant with relatively low loss tangent and electrical conductivity of the mixed-type (i.e., space charge and oxygen ion vacancies) are some of the special features of the La-modified Bi(Sc1/2Fe1/2)O-3 compounds. (C) 2006 Elsevier B.V. All rights reserved.