Microwave dielectric properties of lanthanum based complex perovskites

Abstract

The present investigation discusses the synthesis and dielectric properties of three series of oxides of the formula La2BaTi2M 1-xCuxO9 (where M = Mg, Zn and Cd). The reactions have been carried out via solid state method and all the compositions crystallize in the disordered cubic perovskite structure. Suitable substitution at both A and B sites lead to enhancement in the dielectric properties at high frequencies. The relative permittivity and loss tangent have been measured at X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz) frequencies. The oxides show a dielectric constant of 20-30 while the dielectric loss is quite low in the order of 10-3-10-4 (at 500 kHz) and 10-2 at X and Ku-band. There is scope for further investigations in these systems to realize useful materials for microwave applications. © 2014 Elsevier B.V. All rights reserved.