Cluster and velocity effects on yields and kinetic energy distributions of Li+ desorbed from LiF.
MeV N+ and N2+ ions were used to induce Li+ desorption from LiF. The contributions due to elastic atomic collisions and electronic excitation processes to the sputtering yield could be unambiguously separated. In the case of N2+ ions, a Li+ yield enhancement, i.e., Y(N2+)>2Y(N+), was found only for the electronic process. The maximum sputtering yield was observed in a projectile velocity range where the projectile electronic energy loss still increases. These results are simultaneously explained using the radial distribution of the deposited energy rather than the electronic energy loss.
Pereira
J A
JA
Departamento de Física, Pontifícia Universidade Católica, CP 38071, Rio de Janeiro 22952-970, Brazil.
da Silveira
E F
EF