Synthesis and ferroelectric properties of orientated Bi5ANb4O18 (A = K and Na) ceramics
Synthesis and ferroelectric properties of orientated Bi5ANb4O18 (A = K and Na) ceramics
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DOI：
10.1016/j.jallcom.2008.06.062
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发表时间：
2009-04
影响因子：
6.2
通讯作者：
H. Ogawa;A. Kan;Y. Nakamura
中科院分区：
文献类型：
--
作者：
H. Ogawa;A. Kan;Y. Nakamura
为了提高Bi 5ANb 4 O 18（A=K和Na）陶瓷的铁电性能，采用热锻法制备了取向的Bi 5ANb 4 O 18（A=K和Na）陶瓷。在这项研究中，这种取向陶瓷的形态变化和介电常数的温度依赖性也进行了表征。结果，对于垂直于所施加压力的方向的样品（θ），获得了相对高度取向的陶瓷。Bi 5 KNb 4 O 18（BKN）和Bi 5 NaNb 4 O 18（BNN）陶瓷的样品取向因子（α）分别为0.65和0.70。在BNN陶瓷的情况下，样品（B）的Pr值比没有热锻造的陶瓷的Pr值高40%，而平行于施加压力的方向的样品（//）的Pr值急剧降低。BKN和BNN陶瓷的介电常数的温度依赖性也被测量，这些变化的介电常数强烈依赖于陶瓷的取向。
The orientated Bi5ANb4O18(A=K and Na) ceramics were prepared by using the hot forging in order to improve the ferroelectric properties of the ceramics. The morphological changes and temperature dependence of dielectric constant of such the orientated ceramics were also characterized in this study. As a result, the relatively highly orientated ceramics were obtained for the sample (⊥) which is perpendicular to the direction of the applied pressure. The orientation factors of sample (⊥) for the Bi5KNb4O18(BKN) and Bi5NaNb4O18(BNN) ceramics were 0.65 and 0.70, respectively. In the case of BNN ceramic, the Prvalue of sample (⊥) was 40% higher than that of the ceramic without the hot forging, whereas those of the sample (//), which is parallel to the direction of applied pressure, drastically decreased. The temperature dependence of the dielectric constant of BKN and BNN ceramics was also measured and these variations in the dielectric constant strongly depend on the orientation of the ceramics.