Dispersed Excitation Spectroscopy of Some Weak Transitions of NiF

Abstract

Dispersed excitation spectroscopy, recorded through a spectrometer used as a narrowband filter, made it possible to obtain the rotational analysis of weak blended transitions of NiF. Five electronic transitions, involving a common upper state and five lower states, have been observed in the visible region. One of these transitions (17529.5 cm−1) has been rotationally analyzed. Both the energy splittings between the five new low-lying states and the value of the rotational constant of the lower state of the transition analyzed (B= 0.38511 cm−1) are evidence that these states are not the already known five lower doublet states. Another transition (18348 cm−1) involving the ground2Π3/2state of NiF has been partially analyzed. The upper state (B′ = 0.3702 cm−1) is also linked to the lower2Σ states but not to the components of the2Δ state, ruling out a2Π1/2assignment for this upper state. All these results suggest that the new observed states could be components of quartet states.