3.1 Oxygen Etching Effect
45
Among others, the neutral vanadium clusters have also been studied and were
found to undergo similar etching reactions with oxyge. Figure 3.6 presents a typical
mass abundance of the neutral vanadium clusters at the presence of different reactant
oxygen. As is shown, V n O and V n O 2 series are formed gradually with increased
amount of O 2 introduced into the flow tube reactor. It is notable that the dissociation
channels dominate the reaction of neutral vanadium clusters with oxygen, especially
at the presence of sufficient reactant oxygen. Such dissociation can also be observed
in the collision of V n with He. The major difference between O 2 reaction and He
collision is the intensity change of V 1 after and before the reaction, indicating that
the loss of V atom from V n clusters is preferred in the reaction of V n + O 2 . So, the
Fig. 3.6 a A typical distribution of neutral V n (n = 1–40) clusters photoionized by 177.3 nm deep
ultraviolet (DUV) laser. b–d TOF mass spectra of V n (n = 1–40) reacting with different amount of
5% O 2 /He added into the reaction tube
45
Among others, the neutral vanadium clusters have also been studied and were
found to undergo similar etching reactions with oxyge. Figure 3.6 presents a typical
mass abundance of the neutral vanadium clusters at the presence of different reactant
oxygen. As is shown, V n O and V n O 2 series are formed gradually with increased
amount of O 2 introduced into the flow tube reactor. It is notable that the dissociation
channels dominate the reaction of neutral vanadium clusters with oxygen, especially
at the presence of sufficient reactant oxygen. Such dissociation can also be observed
in the collision of V n with He. The major difference between O 2 reaction and He
collision is the intensity change of V 1 after and before the reaction, indicating that
the loss of V atom from V n clusters is preferred in the reaction of V n + O 2 . So, the
Fig. 3.6 a A typical distribution of neutral V n (n = 1–40) clusters photoionized by 177.3 nm deep
ultraviolet (DUV) laser. b–d TOF mass spectra of V n (n = 1–40) reacting with different amount of
5% O 2 /He added into the reaction tube