Variation of Permittivity with Electric Field in Perovskite‐Like Ferroelectrics
Variation of Permittivity with Electric Field in Perovskite‐Like Ferroelectrics
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DOI：
10.1063/1.1736132
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发表时间：
1961-05
影响因子：
3.2
通讯作者：
H. Diamond
中科院分区：
文献类型：
--
作者：
H. Diamond
考虑了多晶铁电体的模型，其中每个微晶被假定为根据由A. F. Devonshire [Advances in Phys.3，85（1954）]，BaTiO 3。单个晶粒的居里温度取为关于某个选定温度的高斯分布。通过在所有微晶上用该分布求平均来获得介电常数。根据自由能函数，假设电场在给定温度下不是铁电的分布的那些微晶中诱导铁电轴。实验结果表明，在半静态和动态电场中，铁电畴的90°重取向可以忽略不计。尽管后一种假设施加了看似严重的限制，预测一个大的领域的灵敏度。理论和实验数据之间的协议是极好的…
A model is considered for the case of polycrystalline ferroelectrics in which each crystallite is presumed to behave according to a free‐energy function of the type formulated by A. F. Devonshire [Advances in Phys. 3, 85 (1954)] for BaTiO3. The Curie temperatures for the individual grains are taken in a Gaussian distribution about some chosen temperature. The permittivity is obtained by averaging with this distribution over all of the crystallites. In accordance with the free‐energy function, it is assumed that the electric field induces a ferroelectric axis in those crystallites of the distribution which are not ferroelectric at a given temperature. On the basis of experimental evidence, 90° reorientation of domains in the ferroelectric part of the distribution is presumed to be negligible for semistatic and dynamic fields. Despite the seemingly severe restriction imposed by the latter assumption, a large field sensitivity is predicted. Agreement between the theory and experimental data is excellent for ...