Inelastic neutron scattering studies of Crystal Field Levels in PrOs$_4$As$_{12}$

Chi, Songxue; Dai, Pengcheng; Barnes, T.; Kang, H. J.; Lynn, J. W.; Bewley, R.; Ye, F.; Maple, M. B.; Henkie, Z.; Pietraszko, A.

Inelastic neutron scattering studies of Crystal Field Levels in PrOs$_4$As$_{12}$

Authors

Description

We use neutron scattering to study the Pr$^{3+}$ crystalline electric field (CEF) excitations in the filled skutterudite PrOs$_4$As$_{12}$. By comparing the observed levels and their strengths under neutron excitation with the theoretical spectrum and neutron excitation intensities, we identify the Pr$^{3+}$ CEF levels, and show that the ground state is a magnetic $Γ_4^{(2)}$ triplet, and the excited states $Γ_1$, $Γ_4^{(1)}$ and $Γ_{23}$ are at 0.4, 13 and 23 meV, respectively. A comparison of the observed CEF levels in PrOs$_4$As$_{12}$ with the heavy fermion superconductor PrOs$_4$Sb$_{12}$ reveals the microscopic origin of the differences in the ground states of these two filled skutterudites.
7 pages, 7 figures