Hyperfine Fields atCa42in Ferromagnetic Metals and thegFactor of the 3.19-MeV6+State

The hyperfine fields at Ca in ferromagnetic metals have been studied by time-differential measurements on the 3.19-MeV $6^{+}$ state in ${\mathrm{Ca}}^{42}$. The observed hyperfine field in Fe was $H_{\mathrm{hf}}=-100\mathrm{}\pm 9$ kG; preliminary results in Co indicated $H_{\mathrm{hf}}=-70\mathrm{}\pm 15$ kG and in Ni suggested $\left|H_{\mathrm{hf}}\right|<\mathrm{}30\mathrm{}$ kG. These results are in disagreement with predictions by Balabanov and Delyagin. A time-integral measurement in an external magnetic field yielded $g\left(6^{+}\right)=-0.42\mathrm{}\pm 0.03$. The mean lifetime of the $6^{+}$ state was remeasured to be $\tau =7.65\mathrm{}\pm 0.23$ nsec.