MOSSBAUER EFFECT FOR FE57 IN COCL2 AND COF2

The Mössbauer effect for Fe57 in CoCl2 and CoF2 has been measured by using them as sources in a resonant absorption experiment. While the CoCl2 spectra indicate only a 2+ charge state for the Fe57 ion, the CoF2 spectra indicate both a 3+ and a 2+ charge state. When a sample of CoF2 is used as an absorber doped with a small amount of iron enriched in Fe57, however, only 2+ charge state lines appear in the absorption spectra. This is interpreted as resulting from a local environment change associated with Auger aftereffects following K‐capture. The internal magnetic field has been estimated for each compound below its Néel temperature. Values of (49 ± 2) kOe for CoCl2 and (245 ± 2) kOe for CoF2 were found at 10 and 11 °K, respectively, for the field at an Fe2+ nucleus. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim