TY - JOUR
T1 - Sputtering-induced nanometre hole formation in Ni₃Al under intense electron beam irradiation
AU - Tang, Binbing
AU - Jones, Ian
AU - Lai, WS
AU - Bacon, DJ
PY - 2005/6/11
Y1 - 2005/6/11
N2 - The irradiation damage of polycrystalline Ni3Al thin foils of stoichiometric composition by a stationary nanoscale 200 keV. eld emission gun ( FEG)electron probe in a FEI Tecnai F20 ( S) TEM has been investigated. At current densities greater than 10(7) A/m(2), nanometre holes are produced quickly with both [001] and [110] incident electron beam directions. EDX spectra from the irradiated volume have been collected simultaneously during the hole forming process. From the EDX results, preferential surface sputtering of aluminium from Ni3Al has been demonstrated. To understand the underlying physical process of sputtering, modelling based on a combination of molecular dynamics and Monte Carlo simulation has been performed. It appears to reproduce faithfully the overall film sputtering and hole formation processes, but is not capable of predicting the detailed geometry of the hole. It predicts that the sputtering cross-section of Al atoms is much higher than that of Ni atoms, resulting in a very small concentration of Al at the surface. This, together with the increase of surface area during hole formation, explains the preferential Al loss observed from the specimen. Calculated sputtering rates agree well with experiment, and are of the order of magnitude of 10(-8) atoms/ electron.
AB - The irradiation damage of polycrystalline Ni3Al thin foils of stoichiometric composition by a stationary nanoscale 200 keV. eld emission gun ( FEG)electron probe in a FEI Tecnai F20 ( S) TEM has been investigated. At current densities greater than 10(7) A/m(2), nanometre holes are produced quickly with both [001] and [110] incident electron beam directions. EDX spectra from the irradiated volume have been collected simultaneously during the hole forming process. From the EDX results, preferential surface sputtering of aluminium from Ni3Al has been demonstrated. To understand the underlying physical process of sputtering, modelling based on a combination of molecular dynamics and Monte Carlo simulation has been performed. It appears to reproduce faithfully the overall film sputtering and hole formation processes, but is not capable of predicting the detailed geometry of the hole. It predicts that the sputtering cross-section of Al atoms is much higher than that of Ni atoms, resulting in a very small concentration of Al at the surface. This, together with the increase of surface area during hole formation, explains the preferential Al loss observed from the specimen. Calculated sputtering rates agree well with experiment, and are of the order of magnitude of 10(-8) atoms/ electron.
UR - http://www.scopus.com/inward/record.url?scp=27944433390&partnerID=8YFLogxK
U2 - 10.1080/14786430412331331934
DO - 10.1080/14786430412331331934
M3 - Article
VL - 85
SP - 1805
EP - 1817
JO - Philosophical Magazine A: Physics of Condensed Matter, Defects and Mechanical Properties
JF - Philosophical Magazine A: Physics of Condensed Matter, Defects and Mechanical Properties
IS - 17
ER -