Oxygen surface exchange and diffusion studies of La2Mo2O9 in different exchange atmospheres

Determination of 16O and 18O sensitivity factors and charge-exchange processes in low-energy ion scattering

“…9,11,12 Since several processes may occur during the scattering event, a quantitative prediction of the neutralization behaviour (e.g., P þ dependence on the primary ion energy) is required for the selection of the optimal experimental parameters to perform a reliable quantitative LEIS analysis while avoiding timeconsuming calibrations. 6,13,14 In this work, we used the characteristic velocity method in order to study the neutralization behaviour of 4 He þ scattered from 16 O and 18 O and to determine the elemental sensitivity factors. A silica sample has been chosen as a reference material since the preferential sputtering can be neglected at the low ion doses used for the analysis.…”

“…A detailed description of the annealing methodology can be found elsewhere. 16 The samples were analyzed by ToF-SIMS (ION-TOF GmbH, Germany) in order to check the isotopic composition, confirming the 3% and 97% 18 O enrichment of the grown SiO 2 layers.…”

“…The sensitivity and separation of the 18 O and 16 O peaks is strongly affected by the initial energy of the primary ions and the scattering angle. The separation between the final energies (E f ) for scattering by 18 O and 16 O atoms decreases linearly with the initial energy (E i ).…”

“…The separation between the final energies (E f ) for scattering by 18 O and 16 O atoms decreases linearly with the initial energy (E i ). At lower E i the relative peak width (width divided by E i ) increases, since the importance of inelastic processes increases.…”

“…At lower E i the relative peak width (width divided by E i ) increases, since the importance of inelastic processes increases. The experimental peak broadening has been reduced by using a lower E p (1 keV instead of 3 keV) for low E i , which gives a better separation of the 18 O and 16 O peaks (Fig. 1).…”