GRAIN-ORIENTATION AND ELECTRICAL-PROPERTIES OF HOT-FORGED BI4TI3O12 CERAMICS
GRAIN-ORIENTATION AND ELECTRICAL-PROPERTIES OF HOT-FORGED BI4TI3O12 CERAMICS
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DOI：
10.1143/jjap.19.31
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发表时间：
1980-01-01
影响因子：
1.5
通讯作者：
SAKATA, K
中科院分区：
文献类型：
--
作者：
TAKENAKA, T;SAKATA, K
研究了晶粒取向对热锻Bi 4 Ti 3 O 12铁电陶瓷介电性能的影响，并与普通烧结的Bi 4 Ti 3 O 12铁电陶瓷进行了比较。从X射线衍射图计算的晶粒取向度f被认为是大的0.95。用Q计在12 MHz下测量了在垂直于锻造轴的方向和平行于锻造轴的方向上的介电常数ε s和损耗角正切tan δ的温度依赖性，并且观察到相当大的各向异性，例如在约680 C的居里温度下ε s [ε]/ε s [//]= 5。计算了理想（f= 1）和随机（f= 0）晶粒取向两种情况下的回复极化Pr。从磁滞回线观察到的Pr值小于计算值，前者与后者的比例约为82%的热锻陶瓷。
The effect of grain orientation on the dielectric properties of hot-forged ferroelectric Bi 4 Ti 3 O 12 ceramics has been investigated and the properties are compared with ordinarily fired ones. The degree of grain orientation f calculated from X-ray diffraction patterns is found to be as large as 0.95. The temperature dependences of the dielectric constant ε s and loss tangent tan δ are measured with a Q-meter at 12 MHz in the perpendicular [⊥] and parallel [//] directions to the forging axis, and considerable anisotropies, such as ε s [⊥]/ε s [//]= 5 at the Curie temperature of about 680 C, are seen. The remanent polarization P r is calculated for both cases of perfect (f= 1) and random (f= 0) grain orientations. Observed P r values from hysteresis loops are smaller than calculated ones, the ratio of the former to the latter being about 82% for the hot-forged ceramics.