Nuclear Magnetic Resonance in Lead Alloys

Abstract

The ${\mathrm{Pb}}^{207}$ nuclear magnetic resonance has been measured in a series of lead base primary solid solutions containing Cd, In, Sn, Sb, Hg, Tl, and Bi as solutes. The central resonance frequency of ${\mathrm{Pb}}^{207}$ shifts in proportion to the solute concentration and in the opposite direction to be explained by impurity charge screening of the Thomas-Fermi type. The fractional change in Knight shift for all solutes is small $\frac{\ensuremath{\Delta}k}{k}\ensuremath{\approx}0.05 c$. The important parameter in determining the change in Knight shift seems to be the difference in valence between the impurity atoms and the lead atoms. The absorption linewidths broaden rapidly upon the addition of solute. In the absence of a quantitative calculation it is not possible to determine if the small shifts, large widths, and small quadrupole effects of ${\mathrm{In}}^{115}$ are consistent with the theory of long-range oscillations of electronic charge. However, there is evidence that this theory may be capable of explaining our data.