Institut de Physique et de Chimie des Matériaux de Strasbourg UMR 7504 CNRS-UDS, 23 rue du Loess BP43, 67034 Strasbourg cedex 2, France.
J Phys Condens Matter. 2012 May 9;24(18):185502. doi: 10.1088/0953-8984/24/18/185502. Epub 2012 Apr 5.
The electric polarization in the multiferroic GaFeO(3) system is determined from its electronic structure using first principles methods and the modern theory of polarization. By carefully following the electric polarization on a path connecting the polar and centrosymmetric structures, it is found to be -25 μC cm(-2), which is ten times larger than a previous estimation given in the literature a few years ago and two times smaller than the value obtained in a recent similar study. The switching of this electric polarization through a centrosymmetric structure is discussed in terms of the total energy barrier. It is exhibited that such a switching is particularly difficult to achieve in relation to the tetrahedral environment of half of the Ga atoms. The switching via domain wall motion is also discussed.
多铁性 GaFeO(3) 系统的电极化通过第一性原理方法和现代极化理论从其电子结构中确定。通过仔细沿着连接极性和中心对称结构的路径跟踪电极化，发现其值为-25 μC cm(-2)，是几年前文献中给出的先前估计值的十倍，比最近的类似研究中得到的值小两倍。通过中心对称结构切换这种电极化的情况根据总能量势垒进行讨论。结果表明，对于一半 Ga 原子的四面体环境，这种切换特别难以实现。还讨论了通过畴壁运动进行切换的情况。
