Low Temperature Physics: 41, 58 (2015); https://doi.org/10.1063/1.4906337
Crystal field analysis and NMR study of 19F in EuF3 Van Vleck paramagnet
A.V. Savinkov, A.V. Dooglav, B.Z. Malkin, M.S. Tagirov, and S.L. Korableva
Институт физики, Казанский (Приволжский) федеральный университет ул. Кремлевская, 18, г. Казань, 420008, Россия
Received September 16, 2014
The temperature dependence of spin-lattice relaxation rate of 19F nuclei was measured in a powdered sample of EuF3 Van Vleck paramagnet in a broad temperature range 55–300 K. A strong increase of T1-1(T) is observed at T >100 K. It is suggested that the driving mechanism of the 19F nuclear spin-lattice relaxation at T > 100 K is a two-phonon Orbach process that involves the first excited state (Δ1 = 370 K) of the Eu3+ 4f-electron shell. A set of crystal field parameters for EuF3 was calculated in the framework of the exchange charge model. The computed crystal field energies of the Eu3+ ions in EuF3 agree satisfactorily with the experimental data available in literature.
PACS: 76.60.–k Nuclear magnetic resonance and relaxation;
Key words: Van Vleck paramagnets, spin-lattice relaxation, crystal field.
Published online: November 24, 2014