Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Phys Rev Lett. 2009 Oct 2;103(14):147202. doi: 10.1103/PhysRevLett.103.147202. Epub 2009 Sep 30.
The magnetic and ferroelectric properties of the layered geometrically frustrated cluster compound FeTe2O5Br were investigated with single-crystal neutron diffraction and dielectric measurements. An incommensurate transverse amplitude modulated magnetic order with the wave vector q=(1/2,0.463,0) develops below T(N)=10.6(2) K. Simultaneously, a ferroelectric order due to exchange striction involving polarizable Te4+ lone-pair electrons develops perpendicular to q and to Fe3+ magnetic moments. The observed magnetoelectric coupling is proposed to originate from the temperature dependent phase difference between neighboring amplitude modulation waves.
采用单晶中子衍射和介电测量研究了层状几何各向异性受阻团簇化合物 FeTe2O5Br 的磁性和铁电性。在 T（N）=10.6（2）K 以下，出现了一个具有波矢 q=（1/2，0.463，0）的不相干横向幅度调制磁序。同时，由于涉及可极化 Te4+孤对电子的交换压缩，一个垂直于 q 和 Fe3+磁矩的铁电序也发展起来。观察到的磁电耦合被认为源于相邻幅度调制波之间随温度变化的相位差。
