Optical spectroscopy of Mg by Kr+ ion sputtering in presence of O-2

Low energy ion beam sputtering of magnesium exhibits rich and intense optic al spectrum containing a number of Mg(T) and Mg(II) lines. It has been foun d that the emission intensities of Mg(I) and Mg(II) behave differently agai nst the backfilled oxygen pressure. No single explanation can be given for the two different oxygen dependences observed. Considering the similarities with that of secondary ions, it is suggested that the sputtered ions are t he precursors for the excited neutral or ionic species formation. It is tho ught that while the bond-breaking model is appropriate to the excited neutr al atom production, the dominant mechanism for excited secondary ion format ion is the doubly charged secondary ion production by kinetic processes as proposed by Joyes followed by electron capture processes from the surface. (C) 2001 Elsevier Science B.V. All rights reserved.