Chapter 2
Instrumentation for Cluster Science
There are several critical concerns regarding different strategies for producing
gaseous metal atoms/clusters and studying their gas-phase reactivity. In this chapter
we endeavour to summarize all the experimental methods used for cluster preparation and cluster reaction studies. Stress will be laid on a few representative aspects
including cluster sources, cluster growth principles, cluster reaction apparatus and
cluster spectroscopic techniques.
2.1 Cluster Sources
While the utility of molecular beams for studying atomic/molecular collisions has
been well-known for many years, the application of molecule beam technology to
metal clusters requires suitable sources that produce metal atoms/clusters in the gas
phase. A simple way to produce clusters is retrospected to the use of a Knudsen cell
which however was found to be inefficient [1]. With the development of science and
technology, there are many sources used today for an efficient production of free
metal clusters. According to the differences in cluster forming process, the various
cluster sources can be catalogued as:
(a) Supersonic jets, where clusters traverse a skimmer and are ionized by electron
or photon impact and then separated via mass spectrometer;
(b) Gas aggregation sources, which are favoured to produce large clusters;
(c) Surface erosion sources, including those by laser ablation or sputtering;
(d) Pick-up sources, known as the pulsed arc-discharge ion source, etc. [2, 3].
On the other hand, on a basis of the different techniques being involved, the
various cluster sources generally include the following aspects: (i) thermal heated
oven sources; (ii) electrospray ionization; (iii) laser vaporization cluster sources; (iv)
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
Z. Luo and S. N. Khanna, Metal Clusters and Their Reactivity,
https://doi.org/10.1007/978-981-15-9704-6_2
11
Instrumentation for Cluster Science
There are several critical concerns regarding different strategies for producing
gaseous metal atoms/clusters and studying their gas-phase reactivity. In this chapter
we endeavour to summarize all the experimental methods used for cluster preparation and cluster reaction studies. Stress will be laid on a few representative aspects
including cluster sources, cluster growth principles, cluster reaction apparatus and
cluster spectroscopic techniques.
2.1 Cluster Sources
While the utility of molecular beams for studying atomic/molecular collisions has
been well-known for many years, the application of molecule beam technology to
metal clusters requires suitable sources that produce metal atoms/clusters in the gas
phase. A simple way to produce clusters is retrospected to the use of a Knudsen cell
which however was found to be inefficient [1]. With the development of science and
technology, there are many sources used today for an efficient production of free
metal clusters. According to the differences in cluster forming process, the various
cluster sources can be catalogued as:
(a) Supersonic jets, where clusters traverse a skimmer and are ionized by electron
or photon impact and then separated via mass spectrometer;
(b) Gas aggregation sources, which are favoured to produce large clusters;
(c) Surface erosion sources, including those by laser ablation or sputtering;
(d) Pick-up sources, known as the pulsed arc-discharge ion source, etc. [2, 3].
On the other hand, on a basis of the different techniques being involved, the
various cluster sources generally include the following aspects: (i) thermal heated
oven sources; (ii) electrospray ionization; (iii) laser vaporization cluster sources; (iv)
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
Z. Luo and S. N. Khanna, Metal Clusters and Their Reactivity,
https://doi.org/10.1007/978-981-15-9704-6_2
11