Sign of the Nuclear Quadrupole Interaction in Rhenium Metal

Abstract

The sign and magnitude of the nuclear quadrupole splitting in rhenium metal have been determined by heat-capacity measurements down to 19 mK. We find an average coupling constant $\frac{{e}^{2}\mathrm{qQ}}{h}=\ensuremath{-}246\ifmmode\pm\else\textpm\fi{}2$ MHz for the two rhenium isotopes. This gives an electric field gradient at the nucleus of $q=\ensuremath{-}100{q}_{\mathrm{lat}}$, where ${q}_{\mathrm{lat}}$ is the source gradient produced by the ${\mathrm{Re}}^{7+}$ ion cores in the hcp lattice.