Microwave dielectric properties of (1-x)Cu3Nb2O8-xZn(3)Nb(2)O(8) ceramics

The sintering behavior and microwave dielectric properties of (1 - x)Cu3Nb2 O9-xZn(3)Nb(2)O(8) have been investigated using dilatometry, x-ray diffract ion, and a network analyzer. It was found that (1 - x)Cu3Nb2O8-xZn(3)Nb(2)O (8) ceramics have a much lower melting temperature than Zn3Nb2O8 ceramics w ithout Cu3Nb2O8 additives. Samples sintered at 900 degreesC for 2 h exhibit ed densities > 97% of the theoretical density. Cu3Nb2O8 acts as a sintering aid. Two phase regions were identified with increasing Zn3Nb2O8 contents. A Cu3Nb2O8-Zn3Nb2O8 solid solution exists from 0 < x < 0.5 while a mixture of Cu3Nb2O8 and Zn3Nb2O8 exists from 0.5 < x < 1. The microwave dielectric properties correlated to the crystal structure. In Cu3Nb2O8-Zn3Nb2O8 solid solution region, the variation of dielectric properties could be explained by the structure distortion of Cu3Nb2O8 due to electronic anisotropies of C u2+ cations.