Dielectric properties of pyrochlore (Bi1.5Zn0.5)(Nb0.5M1.5)O7 (M=Ti, Sn, Zr, and Ce) dielectrics

Pyrochlore type systems with generic formula (Bi1.5Zn0.5)(Nb0.5M1.5)O7 (M=Ti, Sn, Zr, and Ce) have been synthesized to investigate the influence of M on the dielectric properties. It was found that the incorporation of Sn or Ce resulted in a reasonably reduced dielectric constant. The incorporation of Zr and Ce has led to an appreciable increase in dc conductivity in high temperature. The dc conductivity diminishes as the size of M grows. Dielectric constants, temperature coefficient, and dc conductivity of series ceramics were studied and the relationships among composition, crystal structure, and properties were discussed.