Hyperfine fields at Pb in Fe, Co and Ni lattices and the g-factor of the first 5 − state in 208Pb

Abstract

The integral-reverse-field method of the perturbed angular correlation technique has been used to determine the hyperfine magnetic fields acting at Pb nuclei embedded in iron, cobalt and nickel lattices. The measurements have been performed involving the 1064-570 keV γ-γ cascade in 207Pb. The results when compared with measurements in an external magnetic field give for the hyperfine fields at Pb in Fe, Co and Ni + 660 ± 45, + 430 ± 32 and + 115 ± 15 kG respectively. Making use of the hyperfine fields at Pb we also measured the ratio g(5 −)/ g(3 −) between the g-factors of the second and first excited states in 208Pb to be + 0.036 ± 0.006. This ratio, and the known g-factor of the 3 − state yield g(5 −) = + 0.021 ± 0.007. Finally we discuss our results for the hyperfine magnetic fields on 208Pb using sources of 228Th diffused into Fe, Co and Ni lattices.