Enhanced superhyperfine structure of the EPR spectra of a U3+ ion introduced into the Van Vleck paramagnet LiTmF4
Abstract
The observation of the superhyperfine structure (SHFS) in EPR spectra due to enhanced nuclear magnetism is reported. The X-band spectrum of a U3+ ion introduced into the Van Vleck paramagnet LiTmF4 is measured in the temperature range of 5–20 K and compared with the spectra of LiLuF4:U3+ and LiYF4:U3+ single crystals. The spectra reveal well-resolved and strikingly different SHFS. The SHFS of Li(Lu, Y)F4:U3+ is due to the fluorine ions forming the nearest surroundings of the U3+ ion. The main contribution to the SHFS of the U3+ spectrum in LiTmF4 comes from the Tm3+ ions with a highly enhanced nuclear gyromagnetic tensor.
- Publication:
-
Soviet Journal of Experimental and Theoretical Physics Letters
- Pub Date:
- May 2008
- DOI:
- 10.1134/S002136400806009X
- Bibcode:
- 2008JETPL..87..311A
- Keywords:
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- 75.10.Dg;
- 75.30.Et;
- 76.30.Kg;
- 75.10.Dg;
- 75.30.Et;
- 76.30.Kg;
- Crystal-field theory and spin Hamiltonians;
- Exchange and superexchange interactions;
- Rare-earth ions and impurities