Instantaneous surface work function dependence of MCsn+ molecular ion emission under varying Cs environments

Kinetic energy distributions of MCsn+ (n = 0, 1, 2, …) molecular ions (M - target element to be analyzed and Cs+ - primary ion) emitted in the SIMS process have been studied for Al under varying Cs environments. Experiments were performed for different impact energies and angles. The peak shifts of the energy distributions are due to the changes in the instantaneous surface work functions. The impact angle variation on the work function change is found to be more sensitive than the impact energy variation on the same. Different work function changes for AlCs+ and AlCs2+ ions at the same impact angle signify that the emitting sites of these two species are different.