Effect of external stress on phase diagrams and dielectric properties of epitaxial ferroelectric thin films grown on orthorhombic substrates

被引：0

作者：

吕业刚 ^{[1
]}

邓水凤 ^{[2
]}

龚伦军 ^{[2
]}

杨建桃 ^{[1
]}

机构：

[1] Faculty of Material and Photoelectronic Physics, Xiangtan University, Xiangtan 411105, China

[2] Faculty of Material and Photoelectronic Physics, Xiangtan University, Xiangtan 411105, China Key Laboratory for Advanced Materials and Rheological Properties, Ministry of Education, Xiangtan University, X iangtan 411105, China

来源：

Transactions of Nonferrous Metals Society of China | 2006年 / 04期

基金：

中国国家自然科学基金;

关键词：

external stress; phase transition; dielectric constant; orthorhombic substrate; misfit strain;

D O I：

暂无

中图分类号：

TB43 [薄膜技术];

学科分类号：

0805 ;

摘要：

A Landau-Ginsburg-Devonshire(LD)-type thermodynamic theory was used to describe the effect of external stress on phase diagrams and dielectric properties of epitaxial ferroelectric thin films grown on orthorhombic substrates which induce nonequally biaxial misfit strains in the films plane. The “misfit strain-external stress” and “external stress-temperature” phase diagrams were constructed for single-domain BaTiO3(BT) and PbTiO3(PT) thin films. It is shown that the external stress may lead to the rotation of the spontaneous polarization and a gradual change of its magnitude, which may result in phase transition. Nonequally biaxial misfit strains dependence of the stability of polarization states may be governed by external stress. At room temperature, stress-induced ferroelectric/paraelectric phase transition which occurs in film on cubic substrate does not take place in the ferroelectric thin film grown on orthorhombic substrate. It is also shown that the nonequally misfit strains in the film plane may lead to the appearance of new phases which do not form in films grown on cubic substrates under external stress. The dependence of the dielectric response on the external stress is also studied. It is shown that the dielectric constants of single-domain PT and BT films are very sensitive to the external stress under the given anisotropic misfit strains-temperature conditions. It presents theoretical evidence that the external stress and anisotropic misfit strains can be employed for improving the thin films physical properties.

引用

页码：912 / 916

页数：5