ELECTRICAL ANISOTROPY OF BABI4TI4O15 SINGLE-CRYSTAL
ELECTRICAL ANISOTROPY OF BABI4TI4O15 SINGLE-CRYSTAL
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DOI：
10.2109/jcersj.102.722
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发表时间：
1994-08-01
期刊：
影响因子：
--
通讯作者：
KIM, SK
中科院分区：
文献类型：
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作者：
KIM, SK
本文研究了铋层状铁电体钛酸钡铋（BaBi_4 Ti_4 O_（15））单晶的介电各向异性和直流/交流导电性能，并与多晶样品进行了比较。结果发现，BaBi_4 Ti_4 O_（15），当在1 MHz下测量时，在室温和居里温度下，在平行于铋层的方向（晶体学a（B）-轴）上的介电常数分别比在垂直于铋层的方向（c-轴）上的介电常数高约6倍和58倍。DC/AC电导率在平行于铋层的方向上比在垂直方向上显示出更高的值。另一方面，在平行于铋层的方向上的导电激活能显示出较低的值。多晶样品具有单晶中两个方向的中间性质。复阻抗测量还显示了电介质的各向异性和直流导电特性，即使对于顺电相也是如此。因此，铋层被认为是BaBi 4 Ti4 O 15中的绝缘和顺电层。
Electrical anisotropy of dielectric and DC/AC conducting properties of single crystals of barium bismuth titanate (BaBi4Ti4O15), which is a member of bismuth layer-structured ferroelectrics, has been studied and compared with those of polycrystalline samples. It was found that BaBi4Ti4O15, when measured at 1 MHz, showed about 6 times and 58 times higher dielectric permittivity in the direction parallel to bismuth layer (crystallographic a(b)-axis) than those in the perpendicular direction (c-axis) at room temperature and the Curie temperature, respectively. DC/AC conductivity showed a higher value in the direction parallel to the bismuth layer than those in the perpendicular direction. On the other hand, the activation energy for electric conduction in the direction parallel to the bismuth layer showed a lower value. Polycrystalline samples had intermediate properties of those of the two directions in single crystals. Complex impedance measurements also showed anisotropy in the dielectric and the DC conducting properties even for paraelectric phase. Thus, the bismuth layer was thought to act as an insulating and paraelectric layer in BaBi4Ti4O15.