Microwave Dielectric Properties of New Pyrochlore Type Oxides: Pb3R3Ti7Nb2O26.5 (R = Y, Pr, Nd, Gd or Dy)

Abstract

The microwave dielectric properties of new pyrochlore type oxides: Pb3R3Ti7Nb2O26.5 (R = Y, Pr, Nd, Gd or Dy) have been presented in this paper. These compounds have cubic pyrochlore type structure. Microstructure of the sintered samples reveals well-formed grains in rod and round shapes. The dielectric properties of the materials were studied at low and microwave frequencies. They have relatively high dielectric constant ɛr in the range 70–75 at 1 MHz and ɛr 62–68 range in the microwave frequency region (>3 GHz). The quality factor (Qxf) of these compounds is moderate and best (3550) for Pb3Dy3Ti7Nb2O26.5 compound in the microwave frequency region. This new series of lead containing pyrochlore type oxides having low-temperature sinterability are potential candidates for use as low-temperature cofired ceramic (LTCC) materials for microwave applications such as multilayer filters and other components.