SINTERABILITY IMPROVEMENT OF BA(MG1/3TA2/3)O3 DIELECTRIC CERAMICS

The sinterability of Ba(Mg1/3Ta2/3)O3 ceramics synthesized by solid-state-reaction methods was investigated. The poor sinterability of the present ceramics was found to be primarily due to the presence of satellite secondary phases of Ba5Ta4O15 and Ba4Ta2O9, and the nearly complete densification of Ba(Mg1/3Ta2/3)O3 ceramics was accomplished successfully by controlling the phase constitution of the calcined powders. For this purpose, enhanced ball-milling processes were found to be extremely effective. Moreover, excellent microwave dielectric characteristics (epsilon(r) = 24.5-24.7, Q = 26 000 at 9.8 GHz, and tau(f) = 1.7 p.p.m. degree-C-1) were attained in the dense Ba(Mg1/3Ta2/3)O3 ceramics without additives.