Forbes R, Hockett P, Powis I, Bozek J D, Holland D M P, Pratt S T
Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1A 0R6, Canada.
J Chem Phys. 2021 Nov 21;155(19):194301. doi: 10.1063/5.0068530.
We present a comparison of the photoionization dynamics of the 4d shell of XeF from threshold to 250 eV to those of the prototypical 4d shell of atomic Xe. The new experimental data include spin-orbit and ligand-field-resolved partial cross sections, photoelectron angular distributions, branching fractions, and lifetime widths for the 4d-hole states. The spin-orbit branching fractions and angular distributions are remarkably similar to the corresponding distributions from atomic Xe across a broad energy interval that includes both the intense shape resonance in the f continuum and a Cooper minimum in the same channel. The angular distributions and branching fractions are also in reasonably good agreement with our first-principles theoretical calculations on XeF. Data are also presented on the lifetime widths of the substate-resolved 4d-hole states of XeF. While the trends in the widths are similar to those in the earlier experimental and theoretical work, the linewidths are considerably smaller than in the previous measurements, which may require some reinterpretation of the decay mechanism. Finally, we present new data and an analysis of the Auger electron spectra for ionization above the 4d thresholds and resonant Auger spectra for several pre-edge features.
我们对XeF的4d壳层从阈值到250 eV的光电离动力学与原子Xe的典型4d壳层的光电离动力学进行了比较。新的实验数据包括自旋轨道和配体场分辨的部分截面、光电子角分布、分支比以及4d空穴态的寿命宽度。在包括f连续区强烈的形状共振和同一通道中的库珀极小值在内的宽能量区间内,自旋轨道分支比和角分布与原子Xe的相应分布非常相似。角分布和分支比也与我们对XeF的第一性原理理论计算相当吻合。还给出了XeF子态分辨的4d空穴态寿命宽度的数据。虽然宽度的趋势与早期实验和理论工作中的趋势相似,但线宽比以前的测量结果小得多,这可能需要对衰变机制进行一些重新解释。最后,我们给出了新的数据以及对4d阈值以上电离的俄歇电子能谱和几个预边特征的共振俄歇能谱的分析。