| Title |
Dielectric Properties of BaTiO_3 System Ferroelectric Thick Films Doped with Dy_2O_3 |
| Authors |
노현지(Noh, Hyun-Ji) ; 윤상은(Yun, Sang-Eun) ; 박상만(Park, Sang-Man) ; 안병립(Ahn, Byeong-Lib) ; 이성갑(Lee, Sung-Gap) |
| Keywords |
BaTiO_3 ; Screen-printing ; Thick Films ; Dielectric Properties |
| Abstract |
(Ba,Sr,Ca)TiO_3 powders, which were prepared by sol-gel method using a solution of Ba-, Sr- and Ca-acetate and Ti iso-propoxide, were mixed with organic vehicle and the BSCT thick films were fabricated by the screen-printing techniques on high purity alumina substrates. The structural and dielectirc properties were investigated for various Dy_2O_3 doping contents. As a result of thermal analysis, the exothermic peak was observed at around 670°C due to the formation of the polycrystalline perovskite phase. All BSCT thick films, sintered at 1420°C for 2h, showed the typical XRD patterns of perovskite polycrystalline structure and no pyrochlore phase was observed. The average grain size of the specimens decreased with increasing amount of Dy_2O_3. The average grain size and thickness of the BSCT specimens doped with 0.1 mol% Dy_2O_3 were approximately 1.9μm and 70μm, respectively. The relative dielectric constant decreased and dielectric loss increased with increasing amount of Dy_2O_3, the values of the BSCT thick films doped with 0.1 mol% Dy_2O_3 were 3697 and 0.4% at 1 kHz, respectively. The leakage current densities in all BSCT thick films were less than 10^{-9}A/cm^2 at the applied electric field range of 0-20 kV/cm. |