CSCMR and FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea.
J Phys Condens Matter. 2012 Feb 8;24(5):055503. doi: 10.1088/0953-8984/24/5/055503. Epub 2012 Jan 6.
In order to examine the effects of strong valence band spin-orbit coupling (SOC) in 5d transition metal oxides (TMOs), we have investigated the L(2) and L(3) edge white-line intensities of the x-ray absorption spectra of several 5d TMOs. The white-line intensities at both edges are found to decrease monotonously with increasing 5d electron occupancy, while their ratio showed anomalous behavior for late 5d TMOs (IrO(2), PtO(2), and Au(2)O(3)), deviating significantly from the theoretical value of 2 expected for the case of weak SOC. This observation serves as a clear experimental indication of strong SOC effects in 5d TMOs. We also discussed how the 5d TMOs can have charge transfer effects different from their counterpart 5d elemental metals by making comparative studies. Our works demonstrate the importance of j quantum states due to strong SOC in the 5d system.
为了研究强价带自旋轨道耦合（SOC）在 5d 过渡金属氧化物（TMO）中的作用，我们研究了几种 5d TMO 的 X 射线吸收光谱的 L（2）和 L（3）边白线强度。发现在两个边缘处，白线强度都随 5d 电子占据数的增加单调减小，而它们的比值对于后期 5d TMO（IrO（2）、PtO（2）和 Au（2）O（3））表现出异常行为，与弱 SOC 情况下预期的 2 的理论值显著偏离。这一观察结果清楚地表明了强 SOC 对 5d TMO 的影响。我们还通过比较研究讨论了 5d TMO 如何通过不同于其对应 5d 元素金属的电荷转移效应。我们的工作表明，由于强 SOC，5d 体系中 j 量子态的重要性。
