Thuijs Annaliese E, Li Xiang-Guo, Wang Yun-Peng, Abboud Khalil A, Zhang X-G, Cheng Hai-Ping, Christou George
Department of Chemistry, University of Florida, Gainesville, FL, 32611-7200, USA.
Department of Physics, University of Florida, Gainesville, FL, 32611-7200, USA.
Nat Commun. 2017 Sep 11;8(1):500. doi: 10.1038/s41467-017-00642-0.
The perovskite manganites AMnO and their doped analogues A B MnO (A and B = main group and lanthanide metals) are a fascinating family of magnetic oxides exhibiting a rich variety of properties. They are thus under intense investigation along multiple fronts, one of which is how their structural and physical properties are modified at the nanoscale. Here we show that the molecular compound [CeMnO(OCPh)(HOCPh)] (CeCeMn; hereafter CeMn) bears a striking structural resemblance to the repeating unit seen in the perovskite manganites. Further, magnetic studies have established that CeMn exhibits both the combination of pairwise Mn ferromagnetic and antiferromagnetic exchange interactions, and the resultant spin vector alignments that are found within the 3-D C-type antiferromagnetic perovskites. First-principles theoretical calculations reveal not only the expected nearest-neighbor Mn exchange couplings via superexchange pathways through bridging ligands but also an unusual, direct Mn-Ce-Mn metal-to-metal channel involving the Ce f orbitals.Perovskite manganites exhibit intriguing but poorly understood properties, including multiferroicity. Here, the authors synthesize a CeMn cluster that structurally resembles a perovskite repeat unit, and use this molecular analogue to elucidate mechanisms driving bulk perovskite properties.
钙钛矿锰氧化物AMnO及其掺杂类似物ABMnO（A和B =主族金属和镧系金属）是一类迷人的磁性氧化物，展现出丰富多样的性质。因此，它们正受到多个领域的深入研究，其中之一是它们的结构和物理性质在纳米尺度上是如何被改变的。在这里，我们表明分子化合物[CeMnO(OCPh)(HOCPh)]（CeCeMn；以下简称CeMn）与钙钛矿锰氧化物中所见的重复单元具有惊人的结构相似性。此外，磁性研究已经确定，CeMn既表现出成对的Mn铁磁和反铁磁交换相互作用的组合，也表现出在三维C型反铁磁钙钛矿中发现的自旋矢量排列。第一性原理理论计算不仅揭示了通过桥连配体的超交换途径产生的预期最近邻Mn交换耦合，还揭示了一个涉及Ce f轨道的不寻常直接Mn-Ce-Mn金属到金属通道。钙钛矿锰氧化物表现出有趣但了解甚少的性质，包括多铁性。在这里，作者合成了一种结构类似于钙钛矿重复单元的CeMn簇，并使用这种分子类似物来阐明驱动块状钙钛矿性质的机制。
