Institute of Physical Chemistry
Polish Academy of Sciences
address: Kasprzaka 44/52
01-224 Warsaw, Poland
tel.: +48 22 3432000
fax/tel.: +48 22 3433333, 6325276
Warsaw, 17 November 2010
International surface metrology standards are being developed in Poland
The research on materials' surface layers with spectroscopic methods, extremely
important for nanotechnology, material engineering, microelectronics and many
other areas, requires knowledge of certain physical parameters that are available
in the databases distributed by the US National Institute of Standards and
Technology (NIST). Used by the researchers worldwide, several of these databases
are being developed by Prof. Aleksander Jabłoński from the Institute of Physical
Chemistry of the Polish Academy of Sciences.
Superficial layers of materials, no thicker than several atomic layers, play a key role in many important areas of science and technology, including microelectronics, catalysis or corrosion science. These surface layers are nowadays being studied with different surface sensitive techniques, in particular with electron spectroscopies. Quantitative surface analysis by spectroscopic methods requires, however, taking into consideration certain parameters that are available in the databases distributed by the US National Institute of Standards and Technology (NIST) in Washington. Several of these databases are being developed by Prof. Aleksander Jabłoński from the Institute of Physical Chemistry of the Polish Academy of Sciences. The coming release of the latest of these databases coincides with honouring of Prof. Jabłoński's achievements with the Maria Skłodowska-Curie Scientific Award that is awarded by the Polish Academy of Sciences.
The surface of materials determines the way they interact with the environment. The presence of impurities can, however, change the surface in a hardly predictable manner. "Even when a material contains alien molecules on a few parts per million level, they can migrate to the surface and cover the whole sample. Surface properties of such a substance are then different than those of the material's interior," says Prof. Jabłoński, stressing that the knowledge on actual physical and chemical properties of materials' surfaces is of paramount importance to industries employing the most recent accomplishments of material engineering, microelectronics and various nanotechnologies.
Surface studies employ usually two research methods: photoelectron spectroscopy and Auger electron spectroscopy. In the former, the surface of the sample is irradiated with X-rays and the electrons ejected by photons from surface layers are recorded. In the latter, the material is bombarded with a monoenergetic electron beam, and the energies of electrons emitted due to intra-atomic radiationless transitions (i.e., transitions not accompanied by photon emission) are recorded. As only the electrons ejected from atoms close to the surface have a chance to leave the sample without energy loss, both methods "see" only a few most external atomic layers of the material.
The photoelectron spectroscopy allows to analyze the valence and the chemical form of elements, as well as the distribution of chemical compounds on the material surface, including non-conductors such as substances of biological origin, ceramics or plastics. An electron beam can be focused easier than the x-rays and therefore the Auger electron spectroscopy allows for a better resolution of the element distribution on the surface, approaching in the most recent instruments 10 nanometres.
Accurate analyses by surface sensitive spectroscopies imply necessarily a development of a reliable theory of electron transport in surface region of condensed matter. The mathematical formalism describing the phenomenon is founded on certain parameters that allow a quantitative surface analysis. Extension of theory accomplished by Prof. Jabłoński and his proposals of new parameters resulted in a development of comprehensive databases making life easier for electron spectroscopy users. These compilations - containing parameters such as electron scattering cross sections, mean free paths of electrons and electron attenuation lengths - attracted interest of the US National Institute of Standards and Technology that subsequently started to distribute them. As a result, in years 2001-2010 more than 2000 software packages containing databases developed in the Institute of Physical Chemistry of the PAS have been distributed. These databases are commonly used by researchers worldwide. Recently, Prof. Jabłoński has completed tests of another database, SRD 154, which includes so called modified backscattering factors. The database is scheduled for distribution soon by NIST.
For his work on how to increase the accuracy of surface analyses using spectroscopic techniques, including the preparation of databases for the NIST, Prof. Jabłoński has been just awarded with the prestigious Maria Skłodowska-Curie Scientific Award. The award is awarded annually by the Division III Mathematical, Physical and Chemical Sciences of the Polish Academy of Sciences, alternatively in physics and in chemistry. The award is presented to Polish scientists, non-members of the PAS, whose outstanding and creative work particularly contributed to the development of science. A formal award presentation to Prof. Jabłoński is scheduled to take place in the coming days.
The Institute of Physical Chemistry of the Polish Academy of Sciences (http://www.ichf.edu.pl/) was established in 1955 as one of the first chemical institutes of the PAS. The Institute's scientific profile is strongly related to the newest global trends in the development of physical chemistry and chemical physics. Scientific research is conducted in nine scientific departments. CHEMIPAN R&D Laboratories operating as part of the Institute implement, produce and commercialise specialist chemical compounds to be used, in particular,
in agriculture and pharmacy. The Institute publishes approximately 300 original research papers annually.
Prof. Aleksander Jabłoński
He studied at the Faculty of Chemistry, Szczecin Technical University. He obtained his PhD (1975) and DSc (1982) degrees in the Institute of the Physical Chemistry of the PAS. As a Humboldt Foundation fellow, in years 1983-84 he worked in Prof. Gerhard Ertl's laboratory, a world-class expert in surface chemistry. He has become a professor in 1990. Five years later, he has been awarded with a Golden Cross of Merit for his scientific achievements. Since 2003 he has been the managing director of the Institute of Physical Chemistry of the PAS. In 2007 he was invited by the editors of the Surface Science journal to write an article „Quantification of Surface Sensitive Electron Spectroscopies” to a special volume published in honour of the Nobel Prize awarded to Prof. G. Ertl for his studies on elementary processes on solid surfaces. Prof Jabłoński is a member of scientific councils of several Polish scientific institutions, editorial boards of specialized scientific journals and co-organiser of many conferences. He published 282 scientific papers, with a total number of citations reaching 4400.
CONTACTS TO THE RESEARCHES:
Prof. Aleksander Jabłoński
Institute of the Physical Chemistry of the Polish Academy of Sciences
tel. +48 22 3433331; secretary office: +48 22 3433108, +48 22 3433109
Website of the US National Institute of Standards and Technology NIST with description of the databases for surface analysis.
Prof. Jabłoński developed the databases SRD 64, SRD 71 and SRD 82.
Website of the Institute of Physical Chemistry of the Polish Academy of Sciences (PAS).
Press releases on the Institute of Physical Chemistry of the PAS.
IChF101117b_fot01s.jpg HR: http://ichf.edu.pl/press/2010/11/IChF101117b_fot01.jpg
Prof. Aleksander Jabłoński (left) at the multichamber spectrometer at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw, during visit of ambassador of Japan. (Source: IPC PAS, Grzegorz Krzyżewski)
IChF101117b_fot02s.jpg HR: http://ichf.edu.pl/press/2010/11/IChF101117b_fot02.jpg
A multichamber spectrometer at the Institute of Physical Chemistry of the PAS. The instrument allows for measurements with surface sensitive analytical techniques such as photoelectron spectroscopy and Auger electron spectroscopy. (Source: IPC PAS, Grzegorz Krzyżewski)