Temperature Dependence of theIn115Nuclear-Magnetic-Resonance Spectrum in the Intermetallic Compound InBi

The NMR spectrum of ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}$ in the intermetallic compound InBi was recorded in the temperature range 77-390°K. The Knight shift and the quadrupole coupling constant at the site of the ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}$ nucleus at each temperature have been determined. The Knight shift is positive at higher temperatures, decreases with decreasing temperature, and changes sign at about 230°K, whereas the quadrupole coupling constant, which is also a function of temperature, passes through zero at about 170°K. The results have been discussed in the light of the crystal structure of the compound. It has been shown that core polarization is responsible for the observed negative Knight shift at low temperatures.