REPULSIVE INTERACTION OF CO-LOW ENERGY ION-SCATTERING( AND A PT SURFACE DERIVED FROM VERY)

A high ion-survival probability was observed in ion scattering CO+ on the Pt(001) surface at very low incident energy (less than or equal to 100 eV). This probability is dominated by the repulsive potential in the ion-surface interaction. This repulsive ion-surface interaction is described by two potential energy surfaces. One is the Born-Mayer pot ential in the long-range interaction appearing at incident energies be low 80 eV, and the other is short-range interaction observed in the in cident energy range 75-100 eV at an incidence angle of 60 degrees. The latter potential is due to chemical interaction is predicted by a the oretical work using a Pt-2-CO model cluster. This repulsive ion-surfac e interaction is considered to cause CO+ ion desorption from CO on Pt( 111) and neutral desorption from CO on Pt(001), induced by a ns-pulsed ultraviolet laser in the multiphoton process.