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

The nuclear quadrupole coupling and Knight shift of Be⁹ 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 e²qQh=61.8±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 KBe=-0.0025±(6) at 300^∘{}K and KBe=-0.0035±(6) 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 T₁T=1.66×10⁴ 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.