Silver cofirability differences between Bi1.5Zn0.92Nb1.5O6.92 and Zn3Nb2O8

We have investigated systematically the differences of silver cofirability and microwave dielectric properties between Zn3Nb2O8 and Bi1.5Zn0.92Nb1.5O6.92 (BZN). Two type dopants: 0.29BaCO(3)-0.71CuO (BC) and 0.81MoO(3)-0.19CuO (MC) were used in Zn3Nb2O8 and Bi1.5Zn0.92Nb1.5O6.92 ceramics so they can be cofired with silver. The BC-doped ceramics in general have better dielectric properties than those of MC-doped ceramics. The BC-doped Zn3Nb2O8 exhibits better dielectric properties than those of BC-doped BZN (k = 14.7, Q x f = 8200 GHz versus k = 120.1, Q x f = 1050 GHz). For silver compatibility study, the interfacial behaviors between microwave dielectric materials and silver were investigated by using X-ray diffractometer, scanning electronic microscope, and electronic probe microanalyzer. No new crystalline phase and no silver migration behavior were found in the BC-doped Zn3Nb2O8 ceramics cofired with silver, but slight silver migration was detected for BC-doped BZN. But slight silver migration was detected for MC-doped Zn3Nb2O8 and BZN ceramics cofired with silver. Therefore, the good overall properties of BC-doped Zn3Nb2O8 are suitable for microwave applications. (c) 2006 Elsevier Ltd. All rights reserved.