Energy distributions of niobium and vanadium monomers, dimers, and oxides sputtered by low-energy argon ions

Polycrystalline V and Nb targets were bombarded normally by low energy (Eo ;The Nb energy spectra were measured for a range of incident Ar;For Eo = 900 and 1000 eV, the high energy tail of the Nb;The NbO and VO distributions were obtained while sputtering with background trace amounts of oxygen. Both spectra are monomer-like and do not show the fall off predicted by the single collision direct emission model for surface adsorbates. The VO spectrum is more monomer-like than the NbO spectrum which can be explained using ratios of diatomic binding energies.;The distributions of Nb;At very high O...