Various metal surfaces such as nickel, cobalt, copper, and silver give rise to a reddish luminosity in a stream of N- and O-atoms. Spectroscopic and photographic analysis of these glows indicate the formation of electronically excited molecules on the metal surface which diffuse into the gas phase and radiate. Two parallel processes are involved: the formation of an NO(B2Π), which results in NO β radiation, and the formation of an [Formula: see text] which, in collision, crosses into the N2(B3Π0) state and then radiates back to the [Formula: see text] giving the N2 first positive system. The N2 first positive system observed here shows the strongest bands from v' = 8 and 6; these vibrational levels straddle the [Formula: see text] potential energy curve crossing point. This crossing-over of N2 molecules into the (B3Π0) at this point may explain the observed strong v' = 6 transition in normal N-atom recombination if it is assumed that some of the N-atoms recombine into the [Formula: see text] in addition to the [Formula: see text]state.The N2 second positive system (C3Πu → B3Π0) has also been observed over copper in an N- and O-atom stream. This is most surprising since the N2(C3Πu) has about 1.4 ev more than [Formula: see text]
Diffusion Coefficients of Electronically Excited Molecules
