Bi2O3-ZnO-Nb2O5 system has emerged as a good low sintering (similar to 1050 degrees C) microwave material because it exhibits high dielectric constant and low temperature coefficient of resonance frequency (tau(f)). We have lowered the sintering temperature of Bi1.5Zn0.92M1.5O6.92 (BZN) below 900 degrees C by using 3 wt.% of CuO-based dopants, such as 0.21BaCO(3)-0.79CuO (BC) and 0.81MoO(3)-0.19CuO (MC). The doped BZN exhibits high microwave dielectric constant at 2.3 GHz (k similar to 120). The interfacial behavior between BZN and silver was investigated by using X-ray diffractometer, scanning electronic microscope, and electronic probe microanalyzer. The extent of silver migration of MC and BC dopants is reduced at least by one order of magnitude as compared with V2O5 dopant when the samples was prepared at 900 degrees C for 4 h. Thus, CuO-based dopants can replace V2O5 to lower the sintering temperature of BZN and to be cofired with silver. (c) 2006 Elsevier B.V. All rights reserved.