Nuclear Quadrupole Coupling, Knight Shift, and Spin-Lattice Relaxation Time in Beryllium Metal

The nuclear quadrupole coupling and Knight shift of ${\mathrm{Be}}^9$ have been measured in high-purity beryllium metal at room temperature and at 77°K in magnetic-field strengths up to 25 kOe. The nuclear quadrupole coupling constant is found to have the value $\frac{e^2\mathrm{qQ}}{h}=61.8\mathrm{}\pm 1.8$ kHz, independent of temperature. By contrast, the best estimate of the lattice contribution to the quadrupole coupling is found to be 68±6 kHz, which implies that the conduction-electron contribution opposes that of the lattice. The Knight shift is found to have the values $K_{\mathrm{Be}}=-0.0025\mathrm{}\pm \mathrm{}\left(6\right)\mathrm{}$ at 300°K and $K_{\mathrm{Be}}=-0.0035\mathrm{}\pm \mathrm{}\left(6\right)\mathrm{}$ at 77°K (in percent); the uncertainty given is the standard deviation of the measurements. Measurements of the spin-lattice relaxation time at two temperatures indicate that $T_{1}T=1.66\mathrm{}\times {10}^4$ sec °K with an uncertainty of 10%. These experimental observations can be interpreted in terms of direct-contact and core-polarization contributions, from a predominantly $p$-like band, which partially cancel to yield the small Knight shift.