Isotope shifts are here reported for all stable isotopes of hafnium. The ratios found are: Δσ(180-178): Δσ(178-176):Δσ(176-174) = 100:82.6±3.5:87.6±3.7 and Δσ(180-178):Δσ(l80-179):Δσ(l78-177) = 100:61±9:73±8. The variation of the shifts with neutron number and the even-odd staggering are well beyond experimental error, and are therefore real. Magnitudes of the shifts observed in the spectral lines ranged from 29 to 46 mK. Centroids of the hyperfine-structure patterns due to the odd isotopes were located by using known ratios of the nuclear moments or of the hyperfine-structure parameters. The difference in the electric quadrupole moments between isotopes are discussed from the point of view of isotope-shift anomalies.
WILLIAM L. BARR, "Isotope Shifts in Hafnium," J. Opt. Soc. Am. 48, 658-662 (1958)