Study of Cu_n and Cu_n⁺ (n=1, 2, 3) cluster formation under ion bombardment

Abstract

Yields and energy spectra of neutral and charged particles sputtered from Cu target under 5.5 keV Ar⁺ ion bombardment have been measured. The yield of Cu _n neutrals falls off rapidly with increasing n that can be explained by the recombination model. The yield of Cu _n ⁺ ions depends unmonotonously on n. The ionization probability of sputtered particles is described by an exponential dependence exp[-(I _n - ϕ)/∊₀], where I _n is the ionization potential of Cu _n cluster, ϕ is the work function and ∊₀ is a parameter.

Key Words:

• Sputtering
• clusters
• yields
• ionization probabilities