A study of the structure and dielectric properties for high-valence compensation of Bi3+ ion-doped Ba(FeTa)0.5O3 ceramics
- a Department of Jewelry Technology, Dahan Institute of Technology, Hualien 971, Taiwan
- b Department of Materials Science and Engineering, National United University, Miaoli 360, Taiwan
- c Department of Electronic Engineering, National Formosa University, Huwei, Yunlin, 632 Taiwan
- Received 21 September 2013
- Revised 4 November 2013
- Accepted 5 November 2013
- Available online 13 November 2013
The dielectric constant of Ba0.94Bi0.06(FeTa)0.5O3 were about 8 × 104 -105 measured at 1 kHz.
The activation energy of Ba0.94Bi0.06(FeTa)0.5O3 is about 0.24 eV.
It is concluded that the so-called barrier layer capacitance of Ba1-xBix(FeTa)0.5O3 ceramics.
The higher valence compensation of the Ba1−xBix(FeTa)0.5O3 (x = 0-0.1) system is obtained via a solid-state reaction. The characteristics, including phase formation, microstructure and dielectric properties, are also investigated. In the complex perovskite oxides Ba1-xBix(FeTa)0.5O3 system, the dielectric constant increases when the the Bi3+ ion concentration increases, because there is an increase in valence compensation dipoles. The dielectric constant Ba0.94Bi0.06(FeTa)0.5O3 ceramics sintered at 1250 °C are about 8×104-105, with a low dissipation factor at temperatures between 273-458 K and a frequency of 1 kHz. The temperature-dependent dielectric constant and loss curves, measured in the temperature range, 273-458 K, and at a frequency of 1 kHz, indicate that the samples exhibit typical relaxor behavior over a broad temperature range. Complex impedance spectroscopy shows the presence of barrier layers in bi-phase ceramics, which indicates that the orientation and space charge polarization are dominant for Ba1-xBix(FeTa)0.5O3 dielectric behavior. The frequency dependence of the dielectric loss peak obeys an Arrhenius law, with an activation energy of 0.24 eV, and the relaxation time is 10-9 s.