NMR, high frequency EPR and magnetization studies of YF 3:Tm 3+ and TmF 3

Abstract

Magnetic properties of single crystal and powder samples of thulium fluoride, TmF 3 (orthorhombic Pnma space group), and single crystals of YF 3 doped with the Tm 3+ ions are studied by NMR, high-frequency EPR and dc-magnetometry. It is shown that TmF 3 is a Van Vleck paramagnet. Zero field splitting between two lowest ground state energy levels (ground 3H 6 multiplet) of Tm 3+ ion in TmF 3 crystal lattice is found to be ∼6.5 cm -1. The 19F nuclear spin-lattice relaxation in TmF 3 at liquid helium temperatures is driven by the fluctuating magnetic fields created by Tm 3+ ions occupying the lowest excited singlet.