Electric-field switchable magnetization via the Dzyaloshinskii-Moriya interaction: FeTiO3 versus BiFeO3
Electric-field switchable magnetization via the Dzyaloshinskii-Moriya interaction: FeTiO3 versus BiFeO3
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DOI：
10.1088/0953-8984/20/43/434219
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发表时间：
2008-10-29
影响因子：
2.7
通讯作者：
Fennie, Craig J.
中科院分区：
文献类型：
--
作者：
Ederer, Claude;Fennie, Craig J.
在这篇文章中，我们回顾和讨论了电极化和磁化之间的耦合机制，它最终可以导致电场可切换磁化。其基本思想是，反铁磁性材料中的铁电扭曲可以‘开启’Dzyaloshinskii-Moriya相互作用，从而导致反铁磁亚晶格磁化的倾斜，从而产生净磁化。右箭头M上的磁化强度(M)通过右箭头(M)上的(P)、右箭头(L)上的(L)和右箭头上的(L)的形式的三线性自由能贡献耦合到右箭头P上的极化(P)，其中右箭头上的(L)是反铁磁有序参数。特别是，我们讨论了为什么在R3c FeTiO_3中存在这样的不变量，而在等结构的多铁性BiFeO_3中没有。最后，我们构造了通常允许这种铁电诱导的弱铁磁性的对称群。
In this paper we review and discuss a mechanism for coupling between electric polarization and magnetization that can ultimately lead to electric-field switchable magnetization. The basic idea is that a ferroelectric distortion in an antiferromagnetic material can 'switch on' the Dzyaloshinskii-Moriya interaction which leads to a canting of the antiferromagnetic sublattice magnetizations, and thus to a net magnetization. This magnetization (M) over right arrow M is coupled to the polarization (P) over right arrow P via a trilinear free energy contribution of the form (P) over right arrow (M) over right arrow (L) over right arrow where (L) over right arrow is the antiferromagnetic order parameter. In particular, we discuss why such an invariant is present in R3c FeTiO3 but not in the isostructural multiferroic BiFeO3. Finally, we construct symmetry groups that in general allow for this kind of ferroelectrically-induced weak ferromagnetism.