INVESTIGADORES
BRINGA Eduardo Marcial
artículos
Título:
Sputtering of nano-grains by energetic ions
Autor/es:
E.M. BRINGA; R.E. JOHNSON
Revista:
NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH B - BEAM INTERACTIONS WITH MATERIALS AND ATOMS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2002 vol. 193 p. 365 - 370
ISSN:
0168-583X
Resumen:
Sputtering from grains with a size of tens of nanometers is important in
a number of astrophysical environments having a variety of plasma
properties and can have applications in nano-technology. Since energy
deposition by incident ions or electrons can create `hot' regions in a
small grain, thermal spike (TS) models have been applied to estimate the
sputtering. The excitations produced by a fast ion are often assumed to
form a `hot' cylindrical track. In this paper we use molecular dynamics
(MD) calculations to describe the energy transport and sputtering due
to the creation of a `hot' track in a grain with one quarter million
atoms. We show the enhancement due to grain size and find that TS models
work over a limited range of excitation densities. Discrepancies of
several orders of magnitude are found when comparing our MD results for
sputtering of small dust grains to those obtained by the astrophysical
community using spike models.