Bozin E S, Yin W G, Koch R J, Abeykoon M, Hor Y S, Zheng H, Lei H C, Petrovic C, Mitchell J F, Billinge S J L
Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
Photon Sciences Division, Brookhaven National Laboratory, Upton, NY, 11973, USA.
Nat Commun. 2019 Aug 13;10(1):3638. doi: 10.1038/s41467-019-11372-w.
Fundamental electronic principles underlying all transition metal compounds are the symmetry and filling of the d-electron orbitals and the influence of this filling on structural configurations and responses. Here we use a sensitive local structural technique, x-ray atomic pair distribution function analysis, to reveal the presence of fluctuating local-structural distortions at high temperature in one such compound, CuIrS. We show that this hitherto overlooked fluctuating symmetry-lowering is electronic in origin and will modify the energy-level spectrum and electronic and magnetic properties. The explanation is a local, fluctuating, orbital-degeneracy-lifted state. The natural extension of our result would be that this phenomenon is likely to be widespread amongst diverse classes of partially filled nominally degenerate d-electron systems, with potentially broad implications for our understanding of their properties.
所有过渡金属化合物所基于的基本电子原理是d电子轨道的对称性和填充情况，以及这种填充对结构构型和响应的影响。在这里，我们使用一种灵敏的局域结构技术——X射线原子对分布函数分析，来揭示在一种这样的化合物CuIrS中高温下存在的波动局域结构畸变。我们表明，这种迄今为止被忽视的波动对称性降低起源于电子，并将改变能级谱以及电子和磁性性质。其解释是一种局域的、波动的、轨道简并解除的状态。我们结果的自然延伸是，这种现象可能在各种部分填充的名义上简并的d电子系统中广泛存在，对我们理解它们的性质可能具有广泛的意义。
