Abstract
Recoilless-absorption measurements of the 21.6-keV γ ray of Eu151 in EuCu2Si2 reveal an absorption line which has a strongly temperature-dependent isomer shift. The lines fall at neither the Eu3+ nor the Eu2+ valence positions, but in between. The results are interpreted in terms of fast fluctuations (τ<3.5×10-11 sec) of an electron between the localized 4f level and the conduction band. The difference in energy between the Eu2+ and the Eu3+ states in EuCu2Si2 is found to be about 0.07 eV.
| Original language | English |
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| Pages (from-to) | 1053-1056 |
| Number of pages | 4 |
| Journal | Physical Review Letters |
| Volume | 30 |
| Issue number | 21 |
| DOIs | |
| State | Published - 1973 |