Nuclear-Magnetic-Resonance Study of the Electronic Transition in Near-Equiatomic V-Ru Alloys

For the near-equiatomic V-Ru alloys (46-50-at.% Ru) Chu et al. have observed dramatic changes in the electronic properties of these alloys with an accompanying tetragonal crystallographic distortion. Using the ${\mathrm{V}}^{51}$ nuclear magnetic resonance as a probe of the electronic properties, we have studied the Knight shift $K$ and spin-lattice relaxation rate $R$ in the high-temperature cubic phase and low-temperature tetragonal phase. The dramatic decrease in $R$ and increase in $K$ from the cubic to tetragonal phases are strongly concentration dependent. These results correlate well with the strongly concentration-dependent results for the bulk electronic properties. An analysis of the NMR and susceptibility data shows that the change in the electronic properties from the cubic to tetragonal phases results from a dramatic decrease of the $d$-electron density of states at the Fermi energy, and the $R$ and $K$ are dominated by the $d$-orbital contributions.