Spindynamics in thulium van Vleck paramagnets

Abstract

Three different thulium hydrides (TmH 2 , Tm 0:06 La 0:94 H 2 , TmH 2:73 ) have been investigated by means of nuclear magnetic resonance and static magnetic susceptibility measurements in a temperature range 4--300 K. A careful analysis of the data facilitates the determination of the various crystal field splittings and the type of microscopic magnetic interactions among and between the nuclear subsystems as well as those with the electrons. The selection of the samples used was made in order to clarify a transversal relaxation maximum of the protons at about 35 K. The measured relaxation rates and the resonance positions will be compared to theoretical results obtained by computing the relevant electronic and nuclear spectral densities as function of temperature.

Current progress in the magnetism of rare-earth–hydrogen systems

“…More recently, Udovic et al [19] had determined the magnetic structure of DyD 3 by neutron scattering as AFMstacked FM planes along the c-axis of the type aabb confirming the earlier observed transition temperature of T N = 3.3 K. And finally, let us mention for the sake of completeness, an NMR study by Weizenecker [20] showing that ␥-TmH 2.73 remains a van Vleck paramagnet, just like the cubic ␤-TmH 2 , but the splitting between the non-magnetic ground state, 2 , and the first excited magnetic state, (2) 5 , has decreased by more than 1/3: from 174 to 111 K.…”