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The results of low energy ion scattering are presented and their application to the determination of surface crystallography is described. The focussing of surface wedges and surface lenses is evident from these results. The detection of these focussed ions scattered off subsurface layers has allowed the measurement of the inelastic loss of energetic inert gas ions in the surface region. The energy dependence of the inelastic loss has been investigated and compared to theory. [ABSTRACT FROM PUBLISHER]

Secondary ion energy spectra have been measured for singly charged ions emitted from targets irradiated with 43 keV A+ ions. Targets studied include the 3d transition metals (Sc, Ti, V, Cr, Fe, Ni) Cu and Zn, Zr, Al and Si and the compounds SiO2, Al2O3, NaCl, KCl. Energy spectra were measured in the energy range 1–600 eV. In several cases a peak in the energy spectrum in the region around 200 eV has been found. This is in addition to the usual low energy peaks in the region of 5–10 eV. In many cases the low energy peak was observed to decay steadily with irradiation time or to increase with oxygen pressure. In the case of the cleanest Zn spectrum, only the high energy peak can be detected. The data are discussed in relation to current models of secondary ion emission. We conclude that, in general, elemental metal targets which are clean are characterised by the high energy peak in the secondary ion energy spectrum. The slower ions emitted have been neutralised by electron exchange processes. The low energy peaks in unclean, partially clean, oxide coated or compound targets (NaCl, KCl) arise because the neutralisation of the slower ions is either not as efficient or is not possible. The secondary ion emission model of Blaise and Slodzian could account for the emission of ions from most targets. [ABSTRACT FROM PUBLISHER]

In an experiment which combines photon detection and secondary ion analysis, the influence of single crystal structure on excited particle emission from a (100) Al surface bombarded with 50 KeV Ar+ ions is investigated. The measurements show that both photon and secondary ion yields exhibit characteristic transparency effects when the Al crystal is bombarded under channeling conditions. The angular width of the (110) channel was measured as 16 degrees for the photon yields for types I, II and III spectral lines and Al+ and Al++ secondary ions. The minimum yield for photons was found to depend upon the excitation energy of the excited upper state of the optical transition studied and the minimum yield for ions was dependent upon the kinetic energy of the detected particle. Furthermore the effect of oxygen on the photon and secondary ion yields was studied under conditions in which the incident ion was channeled. [ABSTRACT FROM PUBLISHER]

Single crystals of germanium and indium antimonide, rotated about axes normal to their surfaces were bombarded with 5–15 keV inert gas ions. The resultant variation of the sputtering yield with the angle of ion incidence was followed by means of a modulated mass spectrometric technique capable of monitoring one or more masses in the form of sputtered neutrals and/or secondary ions. Critical angles for channeling, relative reductions in yield and transparency ratios were calculated from the data. The experimental results were compared with predictions of the Onderdelinden and transparency models of sputtering. [ABSTRACT FROM PUBLISHER]