MICROWAVE CHARACTERISTICS OF BAO-TIO2 CERAMICS PREPARED VIA A CITRATE ROUTE

2020-03-26 15:11:17

GHz JH degrees BaTi4O9 Ba2Ti9O20

责任者: CHOY, JH;HAN, YS;SOHN, JH;ITOH, M 单位: TOKYO INST TECHNOL,ENGN MAT RES LAB,YOKOHAMA,KANAGAWA 227,JAPAN. 来源出处: JOURNAL OF THE AMERICAN CERAMIC SOCIETY, v 78, MAY 1995, p 1169- 1172 摘要: Microwave dielectrics of the TiO2-rich BaO-TiO2 system (BaTi4O9 and Ba2Ti9O20) were prepared by the citrate route. Pure and well-crystallized BaTi4O9 and Ba2Ti9O20 particles of nanometer size (30-50 nm) could be obtained by thermal decomposition of citrate gel precursors. After sintering at 1200 degrees-1350 degrees C (for 2-10 h), dense compounds with >90% of theoretical density could be obtained. Dielectric properties of disk-shaped sintered specimens, in the microwave frequency region, were measured in the TE(01 delta) mode, They were found to have excellent microwave characteristics: for BaTi4O9, epsilon(r) = 36, Q = 4900 at 10.3 GHz, and tau(f) = 16 ppm/degrees C; and for Ba2Ti9O20, epsilon(r) = 37, Q = 5300 at 10.7 GHz, and tau(f) = -6.0 ppm/degrees C. 关键词: LEAD; PROTEIN KINASE C; EXOCYTOSIS; CHROMAFFIN CELLS; NOREPINEPHRINE; HIGH DIELECTRIC-CONSTANT; SOL-GEL METHOD; BA2TI9O20 CERAMICS; RESONATOR; PERMITTIVITY; POWDER RESONATOR; PERMITTIVITY; POWDER