Postprint version. Published in Hyperfine Interactions, Volume 72, Issue 1-3, May 1, 1992, pages 45-48.
The definitive version is available at https://doi.org/10.1007/BF02398854.
Longitudinal magnetization of a 57Co in iron metal foil source and an iron metal foil absorber in a uniform external magnetic field results in a simple three-line magnetic hyperfine absorption spectrum. Measurement of the spectral splitting as a function of applied magnetic field yields the 57Fe excited-and ground-state g-factors.