Ab initio study of ferroelectricity in edged PbTiO3 nanowires under axial tension
Ab initio study of ferroelectricity in edged PbTiO3 nanowires under axial tension
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DOI：
10.1103/physrevb.79.024102
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发表时间：
2009-01
影响因子：
3.7
通讯作者：
T. Shimada;Shogo Tomoda;T. Kitamura
中科院分区：
文献类型：
--
作者：
T. Shimada;Shogo Tomoda;T. Kitamura
The atomistic and electronic structures of ${\text{PbTiO}}_{3}$ nanowires with characteristic edges consisting of (100) and (010) surfaces and the crucial role of axial tensile strain on ferroelectricity have been investigated by means of ab initio density-functional theory calculations. Ferroelectricity is enhanced at the edge of the PbO-terminated nanowire because the Pb-O covalent bond that predominates ferroelectric distortions is locally strengthened. On the other hand, a considerable suppression is found in the ${\text{TiO}}_{2}$-terminated nanowire, caused by the charge transfer from the Pb-O site to the Ti-O site. Surprisingly, the smallest PbO-terminated nanowire with a cross section of only one-unit cell can possess ferroelectricity while ferroelectricity disappears in the ${\text{TiO}}_{2}$-terminated nanowires with a cross section smaller than four-by-four cells (diameter of about 17 \AA{}). However, ferroelectricity is recovered by axial tension, where smaller nanowires require larger critical strains.
The atomistic and electronic structures of ${\text{PbTiO}}_{3}$ nanowires with characteristic edges consisting of (100) and (010) surfaces and the crucial role of axial tensile strain on ferroelectricity have been investigated by means of ab initio density-functional theory calculations. Ferroelectricity is enhanced at the edge of the PbO-terminated nanowire because the Pb-O covalent bond that predominates ferroelectric distortions is locally strengthened. On the other hand, a considerable suppression is found in the ${\text{TiO}}_{2}$-terminated nanowire, caused by the charge transfer from the Pb-O site to the Ti-O site. Surprisingly, the smallest PbO-terminated nanowire with a cross section of only one-unit cell can possess ferroelectricity while ferroelectricity disappears in the ${\text{TiO}}_{2}$-terminated nanowires with a cross section smaller than four-by-four cells (diameter of about 17 \AA{}). However, ferroelectricity is recovered by axial tension, where smaller nanowires require larger critical strains.