Tian Ying, Stroppa Alessandro, Chai Yisheng, Yan Liqin, Wang Shouguo, Barone Paolo, Picozzi Silvia, Sun Young
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
CNR-SPIN, UOS L'Aquila, Italy.
Sci Rep. 2014 Aug 14;4:6062. doi: 10.1038/srep06062.
The coexistence of both electric and magnetic orders in some metal-organic frameworks (MOFs) has yielded a new class of multiferroics beyond inorganic materials. However, the coupling between two orders in multiferroic MOFs has not been convincingly verified yet. Here we present clear experimental evidences of cross coupling between electric and magnetic orders in a multiferroic MOF [(CH3)2NH2]Fe(HCOO)3 with a perovskite structure. The dielelectric constant exhibit a hump just at the magnetic ordering temperature TN. Moreover, both the direct (magnetic field control of dielectric properties) and converse (electric field control of magnetization) magnetoelectric effects have been observed in the multiferroic state. This work opens up new insights on the origin of ferroelectricity in MOFs and highlights their promise as magnetoelectric multiferroics.
一些金属有机框架材料（MOF）中电序和磁序的共存产生了一类超越无机材料的新型多铁性材料。然而，多铁性MOF中两种序之间的耦合尚未得到令人信服的验证。在此，我们给出了具有钙钛矿结构的多铁性MOF [(CH3)2NH2]Fe(HCOO)3中电序和磁序之间交叉耦合的明确实验证据。介电常数恰好在磁有序温度TN处出现一个峰。此外，在多铁性状态下还观察到了直接（磁场控制介电性质）和逆（电场控制磁化强度）磁电效应。这项工作为MOF中铁电性的起源开辟了新的见解，并突出了它们作为磁电多铁性材料的前景。
