Evidence for large electric polarization from collinear magnetism in TmMnO3
Evidence for large electric polarization from collinear magnetism in TmMnO3
复制标题
DOI：
10.1088/1367-2630/11/4/043019
复制
发表时间：
2009-04-01
影响因子：
3.3
通讯作者：
Takayama-Muromachi, E.
中科院分区：
文献类型：
--
作者：
Pomjakushin, V. Yu;Kenzelmann, M.;Takayama-Muromachi, E.
自从Kimura等人（2003 Nature 426 - 55）发现反铁磁和铁电有序共存于正交畸变的钙钛矿TbMnO 3中并且强耦合之后，磁电（ME）多铁性领域出现了巨大的研究活动。现在普遍接受的是，TbMnO 3中的铁电性是由破坏晶体对称性并产生极轴的磁性长程有序引起的（Kenzelmann等人，2005 Phys. Rev. Lett. 95 087206）。一个剩下的关键问题是磁序是否能诱导铁电极化，这是大的技术上有用的材料。我们表明，铁电性在正交（o）TmMnO 3共线磁序诱导，其电极化的下限大于以前研究的正交重稀土锰氧化物。晶格常数的温度依赖性提供了大的自旋-晶格耦合效应的进一步证据。我们的实验表明，具有相称的磁基态的正交钙钛矿中的铁电极化可以通过1 μ C cm（-2）阈值，如理论所预测的（Sergienko等人2006 Phys. Rev. Lett. 97 227204; Picozzi等人2007 Phys. Rev. Lett. 99 227201）。
There has been tremendous research activity in the field of magnetoelectric (ME) multiferroics after Kimura et al (2003 Nature 426 55) showed that antiferromagnetic and ferroelectric orders coexist in orthorhombically distorted perovskite TbMnO3 and are strongly coupled. It is now generally accepted that ferroelectricity in TbMnO3 is induced by magnetic long-range order that breaks the symmetry of the crystal and creates a polar axis (Kenzelmann et al 2005 Phys. Rev. Lett. 95 087206). One remaining key question is whether magnetic order can induce ferroelectric polarization that is as large as that of technologically useful materials. We show that ferroelectricity in orthorhombic (o) TmMnO3 is induced by collinear magnetic order, and that the lower limit for its electric polarization is larger than in previously investigated orthorhombic heavy rare-earth manganites. The temperature dependence of the lattice constants provides further evidence of large spin-lattice coupling effects. Our experiments suggest that the ferroelectric polarization in the orthorhombic perovskites with commensurate magnetic ground states could pass the 1 mu C cm(-2) threshold, as predicted by theory (Sergienko et al 2006 Phys. Rev. Lett. 97 227204; Picozzi et al 2007 Phys. Rev. Lett. 99 227201).