Measurement of the nuclear magnetic moments of Ni-57 and Fe-59

The magnetic hyperfine splitting frequencies of (i) Ni-57 in Fe ((NiFe)-Ni-57), (ii) Ni-57 in Ni ((NiNi)-Ni-57), and (iii) Fe-59 in Fe ((FeFe)-Fe-59) were measured with the technique of the nuclear magnetic resonance on oriented nuclei (NMR-ON) at low temperatures. The NMR-ON spectra were observed by detecting the beta-ray asymmetries. The resonance frequencies at zero external magnetic field were deduced from the extrapolation of the external field dependence of the resonance frequencies: nu((NiFe)-Ni-57)=94.23(2) MHz, nu((NiNi)-Ni-57)=30.02(4) MHz, and nu ((FeFe)-Fe-59)=57.719(11) MHz. With the known hyperfine fields of B-HF(NiNi)=-7.406(8) T and B-HF(FeFe)=-33.82(2) T, the magnetic moments of Ni-57 and Fe-59 were determined to be mu(Ni-57)=-0.7975(14)mu(N) and mu(Fe-59)=-0.3358(4)mu(N). The precise value of the hyperfine field of B-HF((NiFe)-Ni-57) was also deduced as -23.25(5) T. The measured values of the magnetic moment are compared with those based on the shell model.