Spin-orbit coupling in iridium-based 5d compounds probed by x-ray absorption spectroscopy
Spin-orbit coupling in iridium-based 5d compounds probed by x-ray absorption spectroscopy
复制标题
DOI：
10.1103/physrevb.86.195131
复制
发表时间：
2012-11-19
影响因子：
3.7
通讯作者：
Kim, Young-June
中科院分区：
文献类型：
--
作者：
Clancy, J. P.;Chen, N.;Kim, Young-June
我们对一系列基于Ir的5d过渡金属化合物进行了x射线吸收光谱（XAS）测量，包括Ir， IrCl3, IrO2, Na2IrO3， Sr2IrO4和Y2Ir2O7。通过比较在Ir -2和L-3吸收边缘观察到的“白线”特征的强度，可以提取有关这些系统中自旋轨道耦合强度的有价值的信息。我们在所有研究的Ir化合物中观察到非常大的非统计分支比，很少或没有依赖于化学成分，晶体结构或电子状态。这一结果证实了新型铱酸盐如Sr2IrO4、Na2IrO3和Y2Ir2O7中存在强烈的自旋轨道耦合效应，并表明即使是简单的铱基化合物如IrO2和IrCl3也可能值得进一步研究。相比之下，对Re基5d化合物，如Re、ReO2、ReO3和Ba2FeReO6的XAS测量显示，统计分支比表明自旋轨道耦合效应可以忽略不计。
We have performed x-ray absorption spectroscopy (XAS) measurements on a series of Ir-based 5d transition metal compounds, including Ir, IrCl3, IrO2, Na2IrO3, Sr2IrO4, and Y2Ir2O7. By comparing the intensity of the "white-line" features observed at the Ir L-2 and L-3 absorption edges, it is possible to extract valuable information about the strength of the spin-orbit coupling in these systems. We observe remarkably large, nonstatistical branching ratios in all Ir compounds studied, with little or no dependence on chemical composition, crystal structure, or electronic state. This result confirms the presence of strong spin-orbit coupling effects in novel iridates such as Sr2IrO4, Na2IrO3, and Y2Ir2O7, and suggests that even simple Ir-based compounds such as IrO2 and IrCl3 may warrant further study. In contrast, XAS measurements on Re-based 5d compounds, such as Re, ReO2, ReO3, and Ba2FeReO6, reveal statistical branching ratios indicative of negligible spin-orbit coupling effects.