The effects of B 2 O 3 addition on the sintering behavior and the dielectric and ferroelectric properties of Ba 0.7 Sr 0.3 TiO 3 (BST) ceramics were investigated. The dielectric and ferroelectric properties of a BST sample with 0.5 wt% B 2 O 3 sintered at <1150°C were as good as those of undoped BST sintered at 1350°C, and the dielectric loss was better. When >1.0 wt% B 2 O 3 was added to BST, the overdoped B 2 O 3 did not form a liquid phase or volatilize; it remained in the samples and formed a secondary phase that lowered the sintering behavior and the dielectric and ferroelectric properties of the BST.

The effects of heating rate on the sintering behavior and the dielectric properties of Ba 0.7 Sr 0.3 TiO 3 ceramics prepared by boron-containing liquid-phase sintering were investigated. When 0.5 wt% B 2 O 3 was added to Ba 0.7 Sr 0.3 TiO 3 , sintering was achieved at ϳ1150°C, and the overdoped B 2 O 3 did not form an adequate amount of liquid phase or volatilize; it remained in the samples and formed a secondary phase. A transition broadening was observed as the heating rate increased. As the heating rate increased, the Curie temperature increased and the maximum dielectric constant (k max ) at the Curie temperature decreased. This result is attributable to a decrease in the diffuseness parameter (␦) and the tetragonality (c/a).

No abstract

No abstract

No abstract