Magnetic Properties of La Sn 3

摘要: The normal-state nuclear-magnetic-resonance (NMR) Knight shifts and spin-lattice relaxation times are reported for ${\mathrm{La}}^{139}$ ${\mathrm{Sn}}^{119}$ in La${\mathrm{Sn}}_{3}$ from 1.6 to 300 \ifmmode^\circ\else\textdegree\fi{}K. New susceptibility data on higher-purity samples 4.2-700 \ifmmode^\circ\else\textdegree\fi{}K which allow a more accurate determination of the $\ensuremath{\chi}$ than previously reported. Above 100 \ifmmode^\circ\else\textdegree\fi{}K, is Curie-Weiss, but it increases by only 6% below 77 time (${T}_{1}T=0.033$ sec \ifmmode^\circ\else\textdegree\fi{}K) isotropic shift (+0.640%) temperature independent, while anisotropic strongly dependent. (+0.207% at 4.2 (${T}_{1}T=1.25$ have dependence an order magnitude smaller expected case strong exchange enhancement La $d$-spin susceptibility. Various partitions NMR discussed using customary approximations transition metals. We find that assumption dominant $d$-orbital has same as gives most reasonable results, although with large number assumptions involved fit not unique. Finally, we discuss nature this orbital point out paramagnetic contributions exist usually neglected may observed dependence.