LASER-RF DOUBLE-RESONANCE SPECTROSCOPY OF HF-177,HF-179

The atomic-beam laser-rf double-resonance technique has been used to make precision measurements of the hyperfine structure (hfs) splittings in the 5d26s2 3FJ (J=2-4) states in Hf177,179 i. By making corrections to the second-order hfs effects, magnetic dipole (A), electric quadrupole (B), and magnetic octupole (C) hfs constants are obtained for the 3FJ states in Hf177,179: The constant C has a strong J dependence as well as does A and B; the isotopic ratio of the constant A between Hf177 and Hf179 has a significant J dependence, indicating J-dependent hyperfine anomalies, while that of the constant C is independent of J within experimental uncertainties, which is taken to be the ratio of the nuclear-ground-state magnetic octupole moments Ω, i.e., Ω(177Hf)/Ω(179Hf)=-0.41(9). It is also pointed out that there is a clear indication of nuclear-spin dependence of the isotopic ratios of C. The single-electron hfs parameters of the 5d electron for the 5d26s2 configuration in Hf i are obtained, and the Sternheimer shielding factor R5d=-0.397(8) is derived. © 1995 The American Physical Society.