Microwave dielectric properties of Ba(Mg,Ta)O/sub 3/-Ba(Co,Nb)O/sub 3/ ceramics

Abstract

Ba(Mg,Ta)03-Ba(Co,Nb)03 ceramics were prepared by the conventional mixed oxide method. The ceramics were sintered at the temperature of 1500 -1575 "C for 5 hours in air.Ba(Mg,Ta)0,-Ba(Co,Nb)03 ceramics have a structure of complex perovskite type, and have peaks of (101),(102),(201),(202) and (212).In the case of the 0.7Ba(Mg,Ta)03-0.3Ba(Co,Nb)03 specimens sintered at 1550°C for 5 hours, dielectric constant, quality factor and temperature coefficient of resonant fiequency(TCRF, z, ) were a good value of 27, 15,712 at 11 Glfz and -1.3 PPM/"C from 25°C to 60"C, respectively. structure of ABO, have excellent dielectric properties, especially the high Q performance. However further modification is needed on the basis of performance improvement, cost reduction, and especially the lower sintering temperature.Therefore, in this study, the dielectric characteristics of the Ba(Mg%Tax)O~-Ba(Co%Nbx)O,[BMT-BCN]ceramics were developed to lower the sintering temperature and to improve the microwave Q-value and zf. The effects of the sintering temperature on the composition of BMT-BCN were investigated. The influences of various compositions and sintering temperatures on the system were studied Also the application for the dielectiic resonator was studied.