{sup 11}B NMR in YbNi{sub 2}B{sub 2}C single crystals: Crossover from localized moments to Fermi-liquid behavior

TLDR: In this article, the authors reported data of NMR in a single crystal of a single metal with a temperature range 1.7-300 K and for two orientations of the external magnetic field with respect to the tetragonal $c$ axis of the crystal.

Abstract: Data of ${}^{11}\mathrm{B}$ NMR in a single crystal of ${\mathrm{YbNi}}_{2}{\mathrm{B}}_{2}\mathrm{C}$ are reported in the temperature range 1.7--300 K and for two orientations of the external magnetic field with respect to the tetragonal $c$ axis of the crystal. For $Tg50\mathrm{K}$ both the Knight shift $K$ and the nuclear spin-lattice relaxation rate ${T}_{1}^{\ensuremath{-}1}$ can be accounted for by the presence of localized $4f$ moments at the ${\mathrm{Yb}}^{3+}$ site which polarize the conduction electrons via the Ruderman-Kittel-Kasuya-Yosida mechanism. On the other hand, at low temperatures, $Tl5\mathrm{K},$ the relaxation rate ${T}_{1}^{\ensuremath{-}1}$ obeys a Korringa-like law with a constant value of ${T}_{1}T$ typical of a normal metal with high density of states at the Fermi level and no localized moments.