Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611, USA.
J Phys Condens Matter. 2011 May 4;23(17):175902. doi: 10.1088/0953-8984/23/17/175902. Epub 2011 Apr 14.
Density functional theory at the level of the local density approximation with the projector augmented wave method is used to determine the structure of 180° domain walls in tetragonal ferroelectric PbTiO(3). In agreement with previous studies, it is found that PbO-centered {100} walls have lower energies than TiO(2)-centered {100} walls, leading to a Peierls potential barrier for wall motion along <010> of ∼36 mJ m(-2). In addition to the Ising-like polarization along the tetragonal axis, it is found that near the domain wall, there is a small polarization in the wall-normal direction away from the domain wall. These Néel-like contributions to the domain wall are analyzed in terms of the Landau-Ginzburg-Devonshire phenomenological theory for ferroelectrics. Similar characteristics are found for {110} domain walls, where OO-centered walls are energetically more favorable than the PbTiO-centered walls.
采用局域密度近似下的投影缀加波方法的密度泛函理论来确定四方铁电 PbTiO(3)中 180°畴壁的结构。与先前的研究一致，发现 PbO 中心的{100}壁的能量低于 TiO(2)中心的{100}壁，导致沿<010>方向的畴壁运动的 Peierls 势垒约为 36 mJ m(-2)。除了沿四方轴的类 Ising 极化外，还发现畴壁附近存在远离畴壁的壁法线方向的小极化。这些畴壁的 Neel 类似贡献根据铁电体的 Landau-Ginzburg-Devonshire 唯象理论进行了分析。对于{110}畴壁也发现了类似的特征，其中 OO 中心的壁在能量上比 PbTiO 中心的壁更有利。
