Rehn, L., Birtcher, R., Donnelly, S. E., Baldo, P. and Funk, L. (2001) Origin of Atomic Clusters during Ion Sputtering. Physical Review Letters, 87 (20). p. 207601. ISSN 0031-9007

Previous studies have shown that the size distributions of small clusters ( n≤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≥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.