Knight shift interaction parameters

All the NMR interaction parameters for zinc metal have been determined from the central and satellite transitions of the Zn spectrum which indicates a value of — 124 ppm for the axial component of the Knight shift. The isotropic component of the Knight shift and the nuclear quadrupole coupling constant have also been determined as a funtion of temperature over the range 149 32 K (Bastow 1996). 

Relatively narrow Zr NMR resonances (11-16 kHz) have been reported in cubic ZrCo and ZrC and tetragonal ZrH2 (Bastow et al. 1992). The spectra of the carbide and hydride show evidence of weak subsidiary structure which is probably due to structural defects. The values of the Knight shift and Ti for ZrH2 have been used in an analysis of the density of states in that material (Zogal et al. 1991). Reported values of the solid state Zr NMR interaction parameters for zirconium compounds are collected in Table 8.12. 

Here, gj is the Land6 g factor of the rare-earth ion, jS the Bohr magneton, and Ko the Knight shift due to band paramagnetism only (see section 1.2.1.). The parameter is a phenomenological exchange constant, which enters from the assumed Hamiltonian for the sf exchange interaction,... 

In the La-H system, the proton diffusive motion also has significant effects on the linewidth, relaxation time T, and Knight shift of the La resonance via the nuclear quadrupole interaction of the La with the fluctuating electrostatic environment resulting from the proton motion. All of these parameters of the La spectrum are strongly temperature and concentration dependent. Schreiber and Cotts (1963) show in detail that the La data confirm and support the model of proton diffusion based on the proton NMR results alone. 

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