hyperfine field

[paper] Perturbed angular distributions with LaBr3 detectors: The $g$ factor of the first 10$^+$ state in $^{110}$Cd reexamined

Perturbed angular distributions with LaBr3  detectors: The g factor of the first 10+  state in 110Cd reexamined

T.J. Gray et al.

doi: 10.1103/PhysRevC.96.054332

The time differential perturbed angular distribution technique with LaBr3 detectors has been applied to the Iπ=11/2 isomeric state (Ex = 846 keV, τ=107 ns) in 107Cd, which was populated and recoil-implanted into a gadolinium host following the 98Mo(12C, 3n)107Cd reaction. The static hyperfine field strength of Cd recoil implanted into gadolinium was thus measured, together with the fraction of nuclei implanted into field-free sites, under similar conditions as pertained for a previous implantation perturbed angular distribution
g-factor measurement on the Iπ=10+ state in 110Cd. The 110Cd g(10+) value was thereby reevaluated, bringing it into agreement with the value expected for a seniority-two νh11/2 configuration.

[paper] Hyperfine fields in the BaFe2As2 family and their relation to the magnetic moment

Hyperfine fields in the BaFe2As2 family and their relation to the magnetic moment

G. Derondeau et al.

doi: 10.1103/PhysRevB.94.214508

The hyperfine field Bhf and the magnetic properties of the BaFe2As2 family are studied using the fully relativistic Dirac formalism for different types of substitution. The study covers electron doped Ba(Fe1−xCox)2As2 and Ba(Fe1−xNix)2As2, hole doped (Ba1−xKx)Fe2As2, and also isovalently doped Ba(Fe1−xRux)2As2 and BaFe2(As1−xPx)2 for a wide range of the concentration x. For the substituted compounds the hyperfine fields show a very strong dependence on the dopant type and its concentration x. Relativistic contributions were found to have a significantly stronger impact for the iron pnictides when compared to bulk Fe. As an important finding, we demonstrate that it is not sensible to relate the hyperfine field Bhf to the average magnetic moment μ of the compound, as it was done in earlier literature.

[Paper] Hyperfine magnetic fields in substituted Finemet alloys

Hyperfine magnetic fields in substituted Finemet alloys

K. Brzózka et al.

doi: 10.1007/s10751-016-1245-1

Transmission Mössbauer spectroscopy was used to determine the hyperfine fields of Finemet-type alloys in form of ribbons, substituted alternatively by Mn, Ni, Co, Al, Zn, V or Ge of various concentration. The comparative analysis of magnetic hyperfine fields was carried out which enabled to understand the role of added elements in as-quenched as well as annealed samples. Moreover, the influence of the substitution on the mean direction of the local hyperfine magnetic field was examined.

[paper] Hyperfine field and hyperfine anomalies of copper impurities in iron

Hyperfine field and hyperfine anomalies of copper impurities in iron

V. V. Golovko et al.

doi: 10.1103/PhysRevC.84.014323

A new value for the hyperfine magnetic field of copper impurities in iron is obtained by combining resonance frequencies from experiments involving β-NMR on oriented nuclei on 59Cu, 69Cu, and 71Cu with magnetic moment values from collinear laser spectroscopy measurements on these isotopes. The resulting value, i.e., Bhf(CuFe) = -21.794(10) T, is in agreement with the value adopted until now but is an order of magnitude more precise. It is consistent with predictions from ab initio calculations. Comparing the hyperfine field values obtained for the individual isotopes, the hyperfine anomalies in Fe were determined to be 59Δ69=0.15(9)% and 71Δ69=0.07(11)%.

[paper] Magnetic moment of 104Agm and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei

Magnetic moment of 104Agm and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei

V.V. Golovko et al.

doi: 10.1103/PhysRevC.81.054323

Nuclear magnetic resonance (NMR/ON) measurements with β- and γ-ray detection have been performed on oriented 104Agg,m nuclei with the NICOLE 3He-4He dilution refrigerator setup at ISOLDE/CERN. For 104Agg (Iπ=5+) the γ-NMR/ON resonance signal was found at ν=266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (<1 K) is found to be |Bhf(AgFe)|=44.709(35) T. A detailed analysis of other relevant data available in the literature yields three more values for this hyperfine field. Averaging all four values yields a new and precise value for the hyperfine field of Ag in Fe; that is, |Bhf(AgFe)|=44.692(30) T. For 104Agm (Iπ=2+), the anisotropy of the β particles provided the NMR/ON resonance signal at ν=627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the magnetic moment μ(104mAg)=+3.691(3) μN, which is significantly more precise than previous results. The magnetic moments of the even-A 102-110Ag isotopes are discussed in view of the competition between the (πg9/2)7/2+-3(νd5/2νg7/2)5/2+ and the (πg9/2)9/2+-3(νd5/2νg7/2)5/2+ configurations. The magnetic moments of the ground and isomeric states of 104Ag can be explained by an almost complete mixing of these two configurations.

[paper] Hyperfine field of einsteinium in iron and nuclear magnetic moment of 254Es

Hyperfine field of einsteinium in iron and nuclear magnetic moment of 254Es

N. Severijns et al.

10.1103/PhysRevC.79.064322

The angular distributions of γ rays and α particles from oriented 250Bk, 253,254Es, and 255Fm nuclei were investigated to extract hyperfine interaction information for these actinide impurities in an iron host lattice. The hyperfine field of einsteinium in iron was found to be |Bhf(EsFe̲ |)=396(32) T. With this value the magnetic moment of 254Es was then determined as |μ|=4.35(41) μN.