Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562, Japan.
Nat Commun. 2015 Jan 9;6:5878. doi: 10.1038/ncomms6878.
Numerous attempts have been made to realize crossed coupling between ferroelectricity and magnetism in multiferroic materials at room temperature. BiFeO3 is the most extensively studied multiferroic material that shows multiferroicity at temperatures significantly above room temperature. Here we present high-field experiments on high-quality mono-domain BiFeO3 crystals reveal substantial electric polarization orthogonal to the widely recognized one along the trigonal c axis. This novel polarization appears to couple with the domains of the cycloidal spin order and, hence, can be controlled using magnetic fields. The transverse polarization shows the non-volatile memory effect at least up to 300 K.
人们已经尝试了很多次，想要在室温多铁材料中实现铁电性和磁性的交叉耦合。BiFeO3 是研究最多的多铁材料，它在远高于室温的温度下表现出多铁性。在这里，我们对高质量单畴 BiFeO3 晶体进行了强场实验，实验揭示了沿三方 c 轴方向的广为人知的铁电体之外的大量正交电极化。这种新的极化似乎与旋轨序畴耦合，因此可以通过磁场进行控制。横向极化在至少 300 K 时表现出非易失性记忆效应。
