High resolution laser spectroscopy of the [13.8]0.5 – X2Δ3/2 and [14.2]1.5 – X2Δ3/2 transitions of hafnium monofluoride (HfF)

Abstract

Laser-induced fluorescence (LIF) spectra of the (0, 0) and (1, 0) bands of the [13.8]0.5 – X2Δ3/2 and [14.2]1.5 – X2Δ3/2 transitions of HfF have been obtained at high resolution (∼120 MHz) using a laser ablation source. Spectra of all five isotopologues, from 180HfF to 176HfF have been clearly resolved and the two most abundant, 180HfF and 178HfF, were chosen for analysis. The rotational levels of the [13.8]0.5 state showed clear Ω – doubling closely resembling that of a 2Σ state in the v = 0 level. Irregularity in the doubling in the v = 1 level and in the isotope shift indicated a strong perturbation affecting this level. The final fit included all the previously analysed bands in the visible region and the doubling of all the Ω = 0.5 states and the isotope effect are examined and discussed.