Title :
Lead magnesium niobate relaxor ferroelectric ceramics of low-firing for multilayer capacitors
Author :
Zhilun, Gui ; Yiushun, Liu ; Hongfei, Sun
Author_Institution :
Dept. of Chem. Eng., Tsinghua Univ., Beijing, China
Abstract :
Lead-magnesium-niobate relaxor ferroelectric ceramics with a high dielectric constant and low sintering temperature for multilayer capacitors have been studied. PMN-PT-PCW and PMN-PT+excess PbO+excess MgO with normal, chemically pure raw materials processed by the direct formation of oxides (mixed-oxides procedure) were sintered at 860-960°C. Values of εmax from 13000 to 18500 (at 1 kHz) and good aging characteristics were obtained. By means of X-ray diffraction analysis, it was found that the amount of pyrochlore phase is less than 2-3% in both the calcined powder and the samples. The dielectric constant of PMN-based ceramics was found to increase with excess MgO and excess PbO. A dense uniform microstructure was obtained at low firing temperatures. The selected-area diffraction pattern shows a ratio of niobium to magnesium of 1:1
Keywords :
capacitors; ceramics; ferroelectric materials; lead compounds; permittivity; sintering; 1 kHz; 860 to 960 C; PbMgO3NbO3; X-ray diffraction analysis; aging characteristics; dense uniform microstructure; high dielectric constant; high permittivity ceramics; low firing temperatures; low sintering temperature; multilayer capacitors; pyrochlore phase; relaxor ferroelectric ceramics; Capacitors; Ceramics; Chemical processes; High-K gate dielectrics; Lead; Magnesium; Niobium compounds; Nonhomogeneous media; Relaxor ferroelectrics; Temperature;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1988. Proceedings., Second International Conference on Properties and Applications of
Conference_Location :
Beijing
DOI :
10.1109/ICPADM.1988.38349
