A theoretical model has
been developed that for the first time introduces the effects on interchanging
energy at an atomic scale into precise dynamic simulations in the interaction
of atoms or molecules of gas with metal surfaces.
The results come from a
team of scientists at the mixed CSIC-UPV/EHU Centre for the Physics of
Materials (CFM) at the Donostia International Physics Center (DIPC) and the
University of the Basque Country (UPV/EHU), working in collaboration with the
Bariloche Atomic Centre in Argentina.
Knowledge about these
types of interactions has implications, the researchers say, for very different
fields of applications, including the making of industrial chemicals.
research, recently published in the Physical Review Letters journal, is an
important advance in the modeling of these reactive processes.
When low-energy gas atoms
or molecules hit the surface of a metal, the atoms or molecules of this gas
react with the surface. Knowing what happens during these reactions is
important, for example, because industrial manufacture of important chemical
products involves the use of metal surfaces as catalysts. Being able to
simulate the dynamics of the interaction of gas/surface reactive processes with
the greatest possible precision is therefore of the highest importance.
To date modeling these
processes has been based on very precise simulations of molecular dynamics, but
hasn’t taken into account so-called inelastic effects, i.e., electronic
excitations or the vibrations of the atoms making up the metal’s crystalline
network. However, recent experiments have shown the need to incorporate in
simulations a description of these types of channels of energy interchange.
It is precisely this that
researchers at the CFM, the DIPC and the UPV/EHU have achieved, they say.
model incorporates these inelastic channels of energy loss and interchange
between the gas and metal surfaces, while maintaining the precision of the calculations
which have not included such effects hitherto.
The model was applied to
the study of two representative systems such as the interaction of molecules of
nitrogen with the surface of tungsten and the interaction of atoms of nitrogen
with silver metal surfaces, demonstrating its validity compared to the results
obtained with existing experimental measures. It was able to reproduce
non-trivial effects observed in the gas atoms or molecules after being
reflected from the metal surfaces.
This work opens up new frontiers in the
study of modeling these elemental reactions at gas/metal surface interactions, the
researchers conclude, enabling quantification of the relevance of the different
processes of interchanging energy.