The spectrum of electronic states at 30000--33000 cm−1 in hafnium
fluoride has been studied using (1+1) resonance-enhanced multi-photon
ionization (REMPI) and (1+1′) REMPI. Six Ω′=3/2 and ten Π1/2
vibronic bands have been characterized. We report the molecular constants for
these bands and estimate the electronic energies of the excited states using a
correction derived from the observed isotope shifts. When either of two closely
spaced Π1/2 electronic states is used as an intermediate state to access
autoionizing Rydberg levels, qualitatively distinct autoionization spectra are
observed. The intermediate state-specificity of the autoionization spectra
bodes well for the possibility of using a selected Π1/2 state as an
intermediate state to create ionic HfF+ in various selected quantum states,
an important requirement for our electron electric dipole moment (eEDM) search
in HfF+.Comment: 11 pages, 8 figures, 1 tabl