Kabbour Houria, Janod Etienne, Corraze Benoît, Danot Michel, Lee Changhoon, Whangbo Myung-Hwan, Cario Laurent
Institut des Matériaux Jean Rouxel, CNRS-Université de Nantes, 2 rue de la Houssinière, BP32229, 44322 Nantes, France.
J Am Chem Soc. 2008 Jul 2;130(26):8261-70. doi: 10.1021/ja711139g. Epub 2008 Jun 6.
The oxychalcogenides A2F2Fe2OQ2 (A = Sr, Ba; Q = S, Se), which contain Fe2O square planar layers of the anti-CuO2 type, were predicted using a modular assembly of layered secondary building units and subsequently synthesized. The physical properties of these compounds were characterized using magnetic susceptibility, electrical resistivity, specific heat, (57)Fe Mossbauer, and powder neutron diffraction measurements and also by estimating their exchange interactions on the basis of first-principles density functional theory electronic structure calculations. These compounds are magnetic semiconductors that undergo a long-range antiferromagnetic ordering below 83.6-106.2 K, and their magnetic properties are well-described by a two-dimensional Ising model. The dominant antiferromagnetic spin exchange interaction between S = 2 Fe(2+) ions occurs through corner-sharing Fe-O-Fe bridges. Moreover, the calculated spin exchange interactions show that the A2F2Fe2OQ2 (A = Sr, Ba; Q = S, Se) compounds represent a rare example of a frustrated antiferromagnetic checkerboard lattice.
氧硫属化合物A2F2Fe2OQ2（A = Sr，Ba；Q = S，Se）包含反CuO2型的Fe2O平面层，通过层状二级结构单元的模块化组装进行预测，随后合成。利用磁化率、电阻率、比热、（57）Fe穆斯堡尔谱和粉末中子衍射测量对这些化合物的物理性质进行了表征，并基于第一性原理密度泛函理论电子结构计算估计了它们的交换相互作用。这些化合物是磁半导体，在83.6 - 106.2 K以下发生长程反铁磁有序，其磁性质可用二维伊辛模型很好地描述。S = 2的Fe(2+)离子之间主要的反铁磁自旋交换相互作用通过角共享的Fe - O - Fe桥发生。此外，计算得到的自旋交换相互作用表明，A2F2Fe2OQ2（A = Sr，Ba；Q = S，Se）化合物代表了受挫反铁磁棋盘晶格的一个罕见例子。
