Measurement of electron affinity of iridium atom and photoelectron angular distributions of iridium anion.
Measurement of electron affinity of iridium atom and photoelectron angular distributions of iridium anion.
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DOI：
10.1063/1.5134535
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发表时间：
2020-01
期刊：
影响因子：
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通讯作者：
Yuzhu Lu;J. Zhao;R. Tang;Xiaoxi Fu;C. Ning
中科院分区：
文献类型：
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作者：
Yuzhu Lu;J. Zhao;R. Tang;Xiaoxi Fu;C. Ning
Bilodeau 及其同事通过基于维格纳阈值定律的方法测定了铱原子的最新电子亲和势值为 1.564 36(15) eV。然而，他们在阈值光脱离实验中观察到与维格纳阈值定律的显着偏差。为了解决这个难题，我们通过慢电子速度图成像方法结合离子阱进行了 Ir- 的高分辨率光电子能谱。测得Ir的电子亲和势为12 614.97(9) cm-1或1.564 057(11) eV。我们发现，通过光脱离通道 Ir-5d86s23F4→Ir5d86sb4F9/2 的 p 波拟合，维格纳阈值定律对于 Ir- 的阈值光脱离仍然有效。还研究了光脱离通道Ir-5d86s23F4→Ir5d76s2a4F9/2和Ir-5d86s23F4→Ir5d86sb4F9/2的光电子角分布。各向异性参数 β 的行为表明两个通道之间存在强烈的相互作用。此外，之前的工作中没有观测到的Ir-的能级3P2经实验确定为高于基态4163.24(16) cm-1。
The latest electron affinity value of an iridium atom is 1.564 36(15) eV, determined via a method based on the Wigner threshold law by Bilodeau and co-workers. However, they observed a significant deviation from the Wigner threshold law in the threshold photodetachment experiment. To address this dilemma, we conducted high-resolution photoelectron spectroscopy of Ir- via the slow-electron velocity-map imaging method in combination with an ion trap. The electron affinity of Ir was measured to be 12 614.97(9) cm-1 or 1.564 057(11) eV. We find that the Wigner threshold law is still valid for the threshold photodetachment of Ir- through a p-wave fitting of the photodetachment channel Ir-5d86s23F4→Ir5d86sb4F9/2. The photoelectron angular distributions of photodetachment channels Ir-5d86s23F4→Ir5d76s2a4F9/2 and Ir-5d86s23F4→Ir5d86sb4F9/2 were also investigated. The behavior of anisotropy parameter β indicates a strong interaction between the two channels. Moreover, the energy level 3P2 of Ir-, which was not observed in the previous works, was experimentally determined to be 4163.24(16) cm-1 above the ground state.