6533b828fe1ef96bd1287874

RESEARCH PRODUCT

Evaluation of the magnetic moment ofRa213

subject

description

The hyperfine field at the nucleus of singly ionized radium has been investigated using the relativistic linked-cluster many-body-perturbation-theory procedure, including the effects of distributed charge and magnetization over the nucleus. The total hyperfine field of 1239 T, when combined with the experimentally observed hyperfine constant for $^{213}\mathrm{Ra}^{+}$, yields a nuclear moment of 0.607(12)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$, in excellent agreement with the experimentally observed moment of 0.6133(18)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$ from Zeeman measurements. Our investigation leads to exchange core-polarization and correlation contributions of 14% and 13%, respectively, of the direct contribution of the 7s valence electron, these ratios being smaller than the corresponding ratios for the isoelectronic atom francium, in keeping with the expected trends for other isoelectronic alkaline-earth-metal ions and alkali-metal atoms. Comparison is made with the results of other calculations of the nuclear moment of $^{213}\mathrm{Ra}$. Possible reasons for the success of the semiempirical Goudsmit-Fermi-Segre formula in predicting the hyperfine field in this ion and related systems will be discussed.