Loading…
Laser ablation source for formation and deposition of size-selected metal clusters
This work describes construction of a source and optimisation of its parameters for production of cluster ion beams using material ablation by the second harmonic of a Nd:YAG laser ( 532 nm ) . The influence of different source parameters such as carrier gas pressure, laser power, delay time between...
Saved in:
Published in: | Review of scientific instruments 2008-07, Vol.79 (7), p.073303-073303 |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | This work describes construction of a source and optimisation of its parameters for production of cluster ion beams using material ablation by the second harmonic of a Nd:YAG laser
(
532
nm
)
. The influence of different source parameters such as carrier gas pressure, laser power, delay time between gas, and laser pulses as well as nozzle configuration on the cluster formation are studied. For the current experiments the laser ablation cluster source was optimized for production of
Co
n
+
cluster ions. Clusters with
n
up to 150 atoms are registered by a time-of-flight mass spectrometer. Deposition of size-selected
Co
50
+
clusters with kinetic energies in the interval of
250
–
4850
eV
/cluster on highly ordered pyrolytic graphite is studied. At the highest impact energies the clusters are implanted. Craters and well-like structures can be seen by scanning tunneling microscopy at impact spots. A decrease in cluster kinetic energy leads to formation of bumplike structures which probably represent damaged graphite areas with incorporated Co atoms. Further decrease in the cluster impact energy to the level of
450
–
250
eV
/cluster creates condition for so-called cluster pinning when the cluster constituents are intact but the energy transferred to the graphite is still enough to produce radiation defects to which the cluster is bound. |
---|---|
ISSN: | 0034-6748 1089-7623 |
DOI: | 10.1063/1.2952503 |