The ultraviolet spectrum of the FeF radical:: A study of the 6Π-X6Δ and 6Φ-X6Δ band systems at 330 and 323 nm respectively

Two band systems of FeF have been recorded at Doppler-limited linewidths by laser-induced fluorescence. The 330-nm system provided data for three subbands of the (0,0) band of the 6 Pi -X-6 Delta system and showed that levels of the (6)Pi (5/2) and (6)Pi (3/2) components are significantly perturbed. In the 323-nm system, the (0,0) band of the (6)Phi -X-6 Delta system was found to be overlapped by the (1,0) band of the (6)Pi -X-6 Delta system. Data were obtained for three subbands of the (1,0) (6)Pi -X-6 Delta system and for five subbands of the (0, 0) (6)Phi -X-6 Delta system. This work considerably extends the previous study by Pouilly et al. (B. Pouilly, J. Schamps, D. J. W. Lumley, and R. F. Barrow, J, Phys. B 11, 2281-2287 (1978)) because it is a higher resolution study with a lower temperature production of FeF by a continuous flow discharge method. The data recorded were combined with millimeter-wave data for FeF in the X6 Delta state and fitted with an effective Hamiltonian to determine the major parameters for FeF in the X-6 Delta, 6(Pi) and 6(Phi) electronic levels. (C) 2001 Academic Press.