Structural and Microwave Dielectric Properties of the ${Ba_5}{B_4}{O_15}$ (B=Ta,Nb) Ceramics with Sintering Temperature

소결온도에 따른 ${Ba_5}{B_4}{O_15}$ (B=Ta,Nb) 세라믹스의 구조 및 마이크로파 유전특성

In this study, structural and microwave dielectric properties of the ${Ba_5}{B_4}{O_{15}}$ (B=Ta, Nb} cation-deficient perovskite ceramics with sintering temperature were investigated. All sample of the ${Ba_5}{B_4}{O_{15}}$ (B=Ta, Nb) ceramics prepared by conventional mixed oxide method and sintered at $1325^{\circ}C{\sim}1575^{\circ}C$. The bulk density and dielectric constant of the ${Ba_5}{Ta_4}{O_{15}}$ ceramics were increased continuously with increasing of sintering temperature. And the bulk density and dielectric constant of the ${Ba_5}{Nb_4}{O_{15}}$ ceramics was increased in $1375^{\circ}C{\sim}1400^{\circ}C$ but decerased in $1425^{\circ}C$. In the case of ${Ba_5}{Ta_4}{O_{15}}$ ceramics sintered at $1475^{\circ}C$ and ${Ba_5}{Nb_4}{O_{15}}$ ceramics sintered at $1400^{\circ}C$, The dielectric constant and quality factor, and temperature coefficient of the resonant frequency (TCRF) were 25.15, 53,105 GHz, $-3.06\;ppm/^{\circ}C$ and, 39.55, 28,052 GHz, $5.7\;ppm/^{\circ}C$ respectively.