Zhang Xian, Liu Kai, He Jian-Qiao, Wu Hui, Huang Qing-Zhen, Lin Jian-Hua, Lu Zhong-Yi, Huang Fu-Qiang
Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Beijing Key Laboratory of Opto-electronic Functional Materials &Micro-nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China.
Sci Rep. 2015 Nov 3;5:15910. doi: 10.1038/srep15910.
Perovskite-related materials have received increasing attention for their broad applications in photovoltaic solar cells and information technology due to their unique electrical and magnetic properties. Here we report three new antiperovskite chalco-halides: Ba3(FeS4)Cl, Ba3(FeS4)Br, and Ba3(FeSe4)Br. All of them were found to be good solar light absorbers. Remarkably, although the shortest Fe-Fe distance exceeds 6 Å, an unexpected anti-ferromagnetic phase transition near 100 K was observed in their magnetic susceptibility measurement. The corresponding complex magnetic structures were resolved by neutron diffraction experiments as well as investigated by first-principles electronic structure calculations. The spin-spin coupling between two neighboring Fe atoms along the b axis, which is realized by the Fe-S···S-Fe super-super exchange mechanism, was found to be responsible for this magnetic phase transition.
由于其独特的电学和磁学性质，钙钛矿相关材料在光伏太阳能电池和信息技术领域的广泛应用受到了越来越多的关注。在此，我们报道了三种新型反钙钛矿硫卤化物：Ba3(FeS4)Cl、Ba3(FeS4)Br和Ba3(FeSe4)Br。发现它们都是良好的太阳光吸收剂。值得注意的是，尽管最短的Fe-Fe距离超过6 Å，但在它们的磁化率测量中观察到在100 K附近出现了意想不到的反铁磁相变。通过中子衍射实验解析了相应的复杂磁结构，并通过第一性原理电子结构计算进行了研究。发现沿b轴的两个相邻Fe原子之间的自旋-自旋耦合是由Fe-S···S-Fe超超交换机制实现的，这是导致这种磁相变的原因。
