Origin of atomic clusters during ion sputtering.
Previous studies have shown that the size distributions of small clusters ( n < or = 40; n = number of atoms/cluster) generated by sputtering obey an inverse power law with an exponent between -8 and -4. Here we report electron microscopy studies of the size distributions of larger clusters ( n > or = 500) sputtered by high-energy ion impacts. These new measurements also yield an inverse power law, but one with an exponent of -2 and one independent of sputtering yield, indicating that the large clusters are produced when shock waves, generated by subsurface displacement cascades, ablate the surface.
Rehn
L E
LE
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Birtcher
R C
RC
Donnelly
S E
SE
Baldo
P M
PM
Funk
L
L