Affiliation:
1. VINČA Institute of Nuclear Sciences, Laboratory of Physical Chemistry, Belgrade
2. Faculty of Technology and Metallurgy, Belgrade
3. VINĈA Institute of Nuclear Sciences, Laboratory of Physical Chemistry, Belgrade
Abstract
Knudsen effusion mass spectrometry or high-temperature method of mass
spectrometry for decades gives new information about saturated vapor of
hardly volatile compounds and it is an important method in the discovery of
many new molecules, radicals, ions and clusters present in the gas phase.
Since pioneering works until now, this method has been successfully applied
to a large number of systems (ores, oxides, ceramics, glass materials,
borides, carbides, sulfides, nitrates, metals, fullerenes, etc) which led to
the establishment of various research branches such as chemistry of clusters.
This paper describes the basic principles of Knudsen cell use for both
identification of chemical species created in the process of evaporation and
determination of their ionization energies. Depending on detected ions
intensities and the partial pressure of each gaseous component, as well as on
changes in partial pressure with temperature, Knudsen cell mass spectrometry
enables the determination of thermodynamic parameters of the tested system. A
special attention is paid to its application in the field of small
heterogeneous and homogeneous clusters of alkali metals. Furthermore,
experimental results for thermodynamic parameters of some clusters, as well
as capabilities of non-standard ways of using Knudsen cells in the process of
synthesis of new clusters are presented herein.
Funder
Ministry of Education, Science and Technological Development of the Republic of Serbia
Publisher
National Library of Serbia
Subject
General Chemical Engineering,General Chemistry