Optical Emission From Ion-Bombarded Nickel and Nickel Oxide

Clean and oxygen-covered nickel and nickel oxide were bombarded by 5keV krypton I ions under a relatively high vacuum. Optical spectra resulting from ion bombardment of the nickel target consist of series of sharp lines attributed to the neutral nickel. These lines were observed in the spectra of clean nickel and nickel oxide at the same wavelengths but with different intensities. The difference in the observed photon yield is discussed in terms of the electron transfer processes between the excited sputtered and electronic levels of the surface.