High-Temperature Capacitor Materials Based on Modified BaTiO3
Abstract
High-temperature capacitor materials sintered at 1120°C were prepared in a BaTiO3 (BT)-Na0.5Bi0.5TiO3 (NBT)-Nb2O5-ZnO-CaZrO3 system. The Curie temperature of BaTiO3 was increased by NBT doping, and a secondary phase occurred when adding ≥5 mol% NBT. The effects of Nb2O5, ZnO, and CaZrO3 on the dielectric properties and the microstructure of BT ceramics doped with 1 mol% NBT were analyzed. The overall dielectric constant decreased when the Nb2O5 content increased, and increased when the ZnO content increased. The dielectric constant peak at the Curie temperature was effectively depressed, and a broad secondary dielectric constant peak appeared at 60°C when the ZnO concentration was ≥4.5 mol%. Significant grain growth was observed by scanning electron microscope (SEM) analysis as the amount of ZnO increased. The high-temperature capacitor specification (-55°C to +175°C, Δ C/ C 25°C less than ±15%) is met when 7 mol% to 8 mol% CaZrO3 is added.
- Publication:
-
Journal of Electronic Materials
- Pub Date:
- May 2009
- DOI:
- 10.1007/s11664-009-0729-z
- Bibcode:
- 2009JEMat..38..706Y
- Keywords:
-
- Barium titanate;
- high-temperature capacitor;
- sodium bismuth titanate;
- electrical properties