TY - JOUR
T1 - Molecular SIMS Ionization Probability Studied with Laser Postionization
T2 - Influence of the Projectile Cluster
AU - Breuer, Lars
AU - Tian, Hua
AU - Wucher, Andreas
AU - Winograd, Nicholas
N1 - Funding Information:
The authors acknowledge financial support of this research by the German Ministry of Science (BMBF) under grant 05K16PG1 “Ion induced materials modification and characterization” as well as the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Projektnummer 278162697 - SFB 1242.
Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - The formation probability of (quasi-)molecular secondary ions released from an organic film under bombardment with a 20 keV cluster ion beam is investigated using combined time-of-flight secondary ion and neutral mass spectrometry (ToF-SIMS/SNMS) experiments. The emitted neutral molecules are postionized after their ejection using strong-field photoionization in an intense short infrared laser pulse. Comparing the (quasi)-molecular secondary ion signal with that of the corresponding neutral molecules, the ionization probability of sputtered intact coronene and guanine molecules is determined. The results are compared between two different projectile cluster ions, namely (i) C 60 + and (ii) Ar n + with n ∼ 1000. It is shown that both projectiles deliver different SNMS spectra, indicating pronounced differences in the collision-induced fragmentation of the emitted molecules. For guanine, the ionization probability obtained with both projectiles is of the same order of magnitude (∼10 -3 ), with the fullerene cluster producing a slightly larger ionization efficiency than the rare gas cluster. For coronene, on the other hand, a substantially lower ionization efficiency is found for the gas cluster projectile.
AB - The formation probability of (quasi-)molecular secondary ions released from an organic film under bombardment with a 20 keV cluster ion beam is investigated using combined time-of-flight secondary ion and neutral mass spectrometry (ToF-SIMS/SNMS) experiments. The emitted neutral molecules are postionized after their ejection using strong-field photoionization in an intense short infrared laser pulse. Comparing the (quasi)-molecular secondary ion signal with that of the corresponding neutral molecules, the ionization probability of sputtered intact coronene and guanine molecules is determined. The results are compared between two different projectile cluster ions, namely (i) C 60 + and (ii) Ar n + with n ∼ 1000. It is shown that both projectiles deliver different SNMS spectra, indicating pronounced differences in the collision-induced fragmentation of the emitted molecules. For guanine, the ionization probability obtained with both projectiles is of the same order of magnitude (∼10 -3 ), with the fullerene cluster producing a slightly larger ionization efficiency than the rare gas cluster. For coronene, on the other hand, a substantially lower ionization efficiency is found for the gas cluster projectile.
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U2 - 10.1021/acs.jpcc.8b10245
DO - 10.1021/acs.jpcc.8b10245
M3 - Article
AN - SCOPUS:85059914500
SN - 1932-7447
VL - 123
SP - 565
EP - 574
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 1
ER -