• Chinese Journal of Chemical Physics
  • Vol. 33, Issue 5, 05000649 (2020)
Li Fang-fang, Ma Yu-jie, Liu Jia-xing, Wang Guan-jun, and Wang Feng-yan*

Abstract

The photodissociation dynamics of AlO at 193 nm is studied using time-sliced ion velocity mapping. Two dissociation channels are found through the speed and angular distributions of aluminum ions: one is one-photon dissociation of the neutral AlO to generate Al($ ^2 $P$ _ \rm{u} $)+O($ ^3 $P$ _ \rm{g} $), and the other is two-photon ionization and then dissociation of AlO$ ^+ $ to generate Al$ ^+ $($ ^1 $S$ _ \rm{g} $)+O($ ^3 $P$ _ \rm{g} $). Each dissociation channel includes the contribution of AlO in the vibrational states $ v $ = 0-2. The anisotropy parameter of the neutral dissociation channel is more dependent on the vibration state of AlO than the ion dissociation channel.

Ⅰ INTRODUCTION

The study of molecular photodissociation dynamics is important to understand the chemical changes of molecules along the potential energy surface, and is also helpful to obtain molecular photon absorption spectra and ionization detection schemes, especially resonance enhanced multiphoton ionization (REMPI) schemes. Over the past 50 years, theoretical [1-15] and experimental [16-23] studies have been conducted on the metal oxide AlO radicals that exist in large amounts in the cosmic space. Based on these previous studies, we have used (1+1) REMPI to detect AlO products through the intermediate state $ D^2 $$ \Sigma^+ $ near 244 nm when studying the oxidation reaction kinetics of aluminum atoms [20]. The main reason is that theoretically, the single photon energy at 244 nm is less than the dissociation energy of AlO, which was estimated as 42496 cm-1 [23], that is, at least at 238 nm, the AlO radical can dissociate.

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Fang-fang Li, Yu-jie Ma, Jia-xing Liu, Guan-jun Wang, Feng-yan Wang. Photodissociation Dynamics of AlO at 193 nm using Time-Sliced Ion Velocity Imaging[J]. Chinese Journal of Chemical Physics, 2020, 33(5): 649
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Received: Jul. 7, 2020
Accepted: Jul. 30, 2020
Published Online: Apr. 21, 2021
The Author Email: Wang Feng-yan (fengyanwang@fudan.edu.cn)