Covalency and vibronic couplings make a nonmagnetic j=3/2 ion magnetic
Covalency and vibronic couplings make a nonmagnetic j=3/2 ion magnetic
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DOI：
10.1038/npjquantmats.2016.29
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发表时间：
2016-12
影响因子：
5.7
通讯作者：
Lei Xu;N. Bogdanov;A. Princep;P. Fulde;J. van den Brink;L. Hozoi
中科院分区：
文献类型：
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作者：
Lei Xu;N. Bogdanov;A. Princep;P. Fulde;J. van den Brink;L. Hozoi
对于4d1和5d1自旋轨道耦合电子构型，经典教科书中讨论的非磁性j= 3/2四重奏基态的概念与观测到的磁性变化不一致。在这里，我们对基于钼和锇的双钙钛矿体系中的4d - 1和5d1离子的电子结构进行了新的研究，并揭示了两类化合物中不同类型的现场多体物理：尽管实验测量的相当大的磁矩和g因子是由于金属d -配体p杂化和4d电子的动态jan - teller相互作用，但它本质上是5d1构型的d -p共价。这些结果强调了自旋轨道相互作用、共价和电子-晶格耦合的微妙相互作用是决定4d和5d量子材料磁性基态性质的主要因素。双钙钛矿结构中的阳离子电荷不平衡进一步表明，可以对t2g和egg水平之间的间隙进行微调，这在氧化物电子的轨道工程中具有很大的潜力。
For 4d 1 and 5d 1 spin–orbit-coupled electron configurations, the notion of nonmagnetic j= 3/2 quartet ground state discussed in classical textbooks is at odds with the observed variety of magnetic properties. Here we throw fresh light on the electronic structure of 4d 1 and 5d 1 ions in molybdenum-and osmium-based double-perovskite systems and reveal different kinds of on-site many-body physics in the two families of compounds: although the sizable magnetic moments and g-factors measured experimentally are due to both metal d–ligand p hybridisation and dynamic Jahn–Teller interactions for 4d electrons, it is essentially d− p covalency for the 5d 1 configuration. These results highlight the subtle interplay of spin–orbit interactions, covalency and electron–lattice couplings as the major factor in deciding the nature of the magnetic ground states of 4d and 5d quantum materials. Cation charge imbalance in the double-perovskite structure is further shown to allow a fine tuning of the gap between the t 2g and e g levels, an effect of much potential in the context of orbital engineering in oxide electronics.