Nuclear Magnetic Resonance in the Metal ReO3:Re185andRe187Knight Shifts and Spin Relaxation Rates

The nuclear magnetic resonances (NMR) of ${}_{}{}^{185}{}_{}{}^{}\mathrm{Re}$ and ${}_{}{}^{187}{}_{}{}^{}\mathrm{Re}$ in Re${\mathrm{O}}_3$ have been studied by pulsed-resonance techniques in the temperature range 1-4°K. The Knight shift, referred to aqueous NaRe${\mathrm{O}}_4$, is found to be $K=(-0.25\mathrm{}\pm 0.02)\%$. The spin-lattice relaxation rates are directly proportional to the absolute temperature, with $T_{1}T=0.23\mathrm{}\pm 0.02$ sec °K for both isotopes. A comparison of these data with previous results for ${}_{}{}^{183}{}_{}{}^{}\mathrm{W}$ in the sodium tungsten bronzes ${\mathrm{Na}}_x\mathrm{W}{\mathrm{O}}_3$ shows that the conduction-band states near the Fermi level are essentially identical in the two metals. The NMR results strongly support the view that these states are predominantly $d$-like.