We present a microscopic study of the electronic and magnetic properties of the spin ladder systems Sr\(_{2}\)Fe\(_{3}\)Ch\(_{2}\)O\(_{3}\) (Ch=S, Se) based on density functional calculations and on ab initio-derived effective models. We discuss explicitly the nature of the exchange paths and provide quantitative estimates of magnetic exchange couplings. Although both compounds have similar crystal structures, the values of magnetic exchange interactions are slightly greater for S compound than Se compound. A microscopic modelling based on analysis of the electronic structure of these systems put Sr\(_{2}\)Fe\(_{3}\)Ch\(_{2}\)O\(_{3}\) (Ch=S, Se) in the interesting class of 2-D AFM spin, S = 2 ladder systems.

我们目前对自旋阶梯系统Sr \（_ {2} \） Fe \（_ {3} \） Ch \（_ {2} \） O \（_ {3} \）（Ch = S，Se）基于密度泛函计算和从头算来的有效模型。我们明确讨论了交换路径的性质，并提供了磁交换耦合的定量估计。尽管两种化合物具有相似的晶体结构，但S化合物的磁交换相互作用值略大于Se化合物。基于对这些系统电子结构的分析的微观建模将Sr \（_ {2} \） Fe \（_ {3} \） Ch\（_ {2} \） O \（_ {3} \）（Ch = S，Se）在有趣的2-D AFM自旋中，S = 2梯形系统。