Pb207Nuclear Magnetic Resonance in PbSe

Abstract

The temperature dependence of the ${\mathrm{Pb}}^{207}$ nuclear magnetic resonance has been studied from 183 to 428°K in the semiconducting compound PbSe. Relatively large field shifts are observed which can be interpreted in terms of a temperature-dependent Knight shift. The temperature dependence of the $p$-type sample was observed to be proportional to $T^{\frac{1}{2}}\exp (-\frac{E}{\mathrm{kT}})$, where $E=0.023\mathrm{}$ eV. Supplementary measurements of the carrier density allowed the calculation of the position of the Fermi energy and the free-carrier susceptibility. Quantitative estimates from the Knight shift of the susceptibility are reasonable. The use of a previously determined temperature-dependent effective mass is found to be compatible with these measurements. The results are consistent with predictions from the calculated band structure in regard to the symmetry type and the mixing coefficients of the wave functions. Measurements of $n$-type PbSe doped with 0.8% ${\mathrm{Cu}}^{2+}$, 0.3% ${\mathrm{V}}^{3+}$, and 2% ${\mathrm{Eu}}^{3+}$ showed a large temperature-dependent shift which is attributed to the mechanism of electron transfer. Relative to the Knight shift, this shift is observed to be proportional to $\frac{1}{T}$.