Knight Shift Studies of Transition Metals: Rhodium and Rhodium Intermetallic Compounds

The temperature dependence of the nuclear magnetic resonance (nmr) of ${\mathrm{Rh}}^{103}$ in rhodium metal has been examined. From the linearity of the Knight shift ($K$) versus susceptibility ($\chi$) plot, it is deduced that all of the temperature variation in $\chi$ is of $d$-spin origin; the slope of the $K$-versus-$\chi$ curve yields a core-polarization hyperfine field of -0.323×${10}^6$ Oe spin. An analysis of the separate contributions to the $K$ and $\chi$ based on a two-band model is given, and some considerations offered on the exchange enhancement of $\chi$ in the Rh-Pd alloy system. Nmr has also been observed and the Knight shifts determined in the intermetallic compounds Rh${\mathrm{Sn}}_2$, La${\mathrm{Rh}}_2$, RhSi, Th${\mathrm{Rh}}_3$, and U${\mathrm{Rh}}_3$. A value of the ${\mathrm{Rh}}^{103}$ nuclear moment ${\mu }^{103}=-0.0879\mathrm{}\pm 0.0001{\mu }_n$ (uncorrected for diamagnetic shielding) is obtained.