Neutralization of low-energy Ne+ ions scattered from metal surfaces: studyby mass-resolved ion-scattering spectrometry

An updated dual-isotope method by mass-resolved ion-scattering spectrometry using simultaneously two isotopes of Ne+ as primary-ion beam was developed for the study of neutralization phenomena occurring with low-energy (0.5-1 .5 keV) ions scattered from the surface of noble/transition metals (Cu, Ag, Au and Pt). Data for the characteristic velocity nu (c) were estimated, na mely 2.05 x 10(5) m s(-1) (Cu), 2.15 x 10(5) m s(-1) (Ag), 1.90 x 10(5) m s (-1) (Au) and 1.67 x 10(5) m s(-1) (Pt), and no monotone dependence of the ion-survival probability P+ on the reciprocal velocity was evaluated. The e mpirical formula for P+(1/nu), containing an additional term dependent on t he reciprocal velocity, was suggested. The presented results have confirmed the anomalous dependence of P+(1/nu) already observed in earlier low energ y ion scattering studies. (C) 2000 Elsevier Science B.V. All rights reserve d.