Secondary ion mass-spectrometry of tungsten-based compound systems

The emission of negative secondary ions of different composition sputtered by O2+ ions from tungsten-based compoundsystems has been compared. Relative yields of negative ions of different nature, ion energy distribution, and the effect of oxygen, carbon and potassium additives on ion emission have been studied. The results are discussed taking into account the variation of the electron affinity energy near the surface and the shape of the potential curves for neutral and ionic state. The use of complex negative ions is shown to be advantageous in SIMS analysis of compound systems