Normandie Université, UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, France.
Normandie Université, ENSICAEN, UNICAEN, CEA, CNRS, CIMAP, UMR 6252, BP 5133, F-14070 Caen Cedex 05, France.
J Chem Phys. 2017 Oct 28;147(16):164301. doi: 10.1063/1.5001113.
The molecular electronic states of the SiO dication have been investigated in a joint theoretical and experimental analysis. The use of a tip-shaped sample for tomographic atom probe analysis offers the unique opportunity to produce and to analyze the lifetime of some excited states of this dication. The perturbation brought by the large electric field of the polarized tip along the ion trajectory is analyzed by means of molecular dynamics simulation. For the typical electric fields used in the experiment, the lowest energy triplet states spontaneously dissociate, while the lowest energy singlet states do not. We show that the emission process leads to the formation of some excited singlet state, which dissociates by means of spin-orbit coupling with lower-energy triplet states to produce specific patterns associated with Si + O and Si + O dissociation channels. These patterns are recorded and observed experimentally in a correlated time-of-flight map.
SiO 二价阳离子的分子电子态已通过理论和实验联合分析进行了研究。采用尖端形状的样品进行断层原子探针分析，为产生和分析这种二价阳离子的一些激发态的寿命提供了独特的机会。通过分子动力学模拟分析了沿离子轨迹极化尖端带来的扰动。对于实验中使用的典型电场，最低能量三重态自发解离，而最低能量单重态不会。我们表明，发射过程导致形成一些激发的单重态，这些单重态通过自旋轨道耦合与低能三重态解离，产生与 Si + O 和 Si + O 解离通道相关的特定图案。这些图案在相关的飞行时间图谱中被记录和观察到。
