Abstract
Lead based complex perovskite compounds with a general formula ABO_3 (A = mono or divalent ion, B = tetra or pentavalent ions) are considered to be important materials for a wide range of piezoelectric, pyroelectric and ferroelectric devices such as transducers, computer memory and display, pyroelectric sensors, electro-optical modulators etc [1-6]. It has been observed that by suitable substitutions at the Pb and /or Ti sites of PbTiO_3, a large number of charge neutral or deficient compounds can be prepared [7-9], satisfying the following conditions: (a) charge neutrality and (b) tolerance factor, t, [10] as t = rA + r0/2~(2/1) (rB + R0) where rA is the average ionic radius of the A site atoms; rB is the average ionic radius of site atoms and r0 is the ionic radius of O~(2-). In view of the above importance, we have carried, out systematic and extensive studies on the structural, dielectric and electric properties of ATeO_3(A = Ca, Mg, Ba, Sr). In this paper we report our work on CaTeO_3.
NSTL