TY - JOUR
T1 - Surface effects on damage production during ion bombardment
T2 - A molecular dynamics study
AU - Ghaly, Mai
AU - Averback, R. S.
AU - Diaz de la Rubia, T.
N1 - Funding Information:
The researchw as supportedb y the DOE, Basic Energy Sciences under grant DEFG02-91ER4.5439. Grants of computer time from the National Energy Research Computer Center at Livermore, CA, the National Center for SupercomputingA pplications at UIUC, and the Materials Research Laboratory at UIUC are gratefully acknowledged.
PY - 1995/8
Y1 - 1995/8
N2 - Molecular dynamics investigations of self-ion bombardment of Au, Cu, Ge, and Pt were performed with ion energies in the range of 5-20 keV. These simulations revealed that the mechanisms of damage production near surfaces can be far different than those in the bulk. Local melting was observed to be a fundamental element in all of the simulations. In the metals, where the volume of melting is positive, pressure was created within the molten cascade core, and this led to the flow of atoms onto the surface. Upon solidification, relatively few atoms were able to return to lattice sites below the surface, leading to the formation of islands on the surface and dislocation loops of vacancy character, below. Similar effects of melting were obtained for Ge, but since the volume of melting is negative, a somewhat different damage mechanism arises. The simulations also provide new insight about the nature of nonlinear sputtering in metals with high atomic numbers.
AB - Molecular dynamics investigations of self-ion bombardment of Au, Cu, Ge, and Pt were performed with ion energies in the range of 5-20 keV. These simulations revealed that the mechanisms of damage production near surfaces can be far different than those in the bulk. Local melting was observed to be a fundamental element in all of the simulations. In the metals, where the volume of melting is positive, pressure was created within the molten cascade core, and this led to the flow of atoms onto the surface. Upon solidification, relatively few atoms were able to return to lattice sites below the surface, leading to the formation of islands on the surface and dislocation loops of vacancy character, below. Similar effects of melting were obtained for Ge, but since the volume of melting is negative, a somewhat different damage mechanism arises. The simulations also provide new insight about the nature of nonlinear sputtering in metals with high atomic numbers.
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U2 - 10.1016/0168-583X(95)80116-4
DO - 10.1016/0168-583X(95)80116-4
M3 - Article
AN - SCOPUS:33745004995
SN - 0168-583X
VL - 102
SP - 51
EP - 57
JO - Nuclear Inst. and Methods in Physics Research, B
JF - Nuclear Inst. and Methods in Physics Research, B
IS - 1-4
ER -