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.

The time differential perturbed angular distribution technique with LaBr₃ detectors has been applied to the I^π=11/2⁻ isomeric state (E_x = 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 I^π=10⁺ state in ¹¹⁰Cd. The ¹¹⁰Cd g(10⁺) value was thereby reevaluated, bringing it into agreement with the value expected for a seniority-two νh_11/2 configuration.

Nov 29, 2017 by Theo g factor 0

[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.

Dec 13, 2016 by Theo theory 0

[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.

Mar 18, 2016 by Theo g factor 0

[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., B_hf(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)%.

Jul 22, 2011 by Theo g factor 0

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

Magnetic moment of ¹⁰⁴Ag^m 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 ¹⁰⁴Ag^g,m nuclei with the NICOLE ³He-⁴He dilution refrigerator setup at ISOLDE/CERN. For ¹⁰⁴Ag^g (I^π=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 |B_hf(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, |B_hf(AgFe)|=44.692(30) T. For ¹⁰⁴Ag^m (I^π=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) μ_N, 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 (πg_9/2)^7/2+-3(νd_5/2νg_7/2)^5/2+ and the (πg_9/2)^9/2+-3(νd_5/2νg_7/2)^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.

May 28, 2010 by Theo experiment g factor theory 0

[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 |B_hf(EsFe̲ |)=396(32) T. With this value the magnetic moment of ²⁵⁴Es was then determined as |μ|=4.35(41) μ_N.

Jun 29, 2009 by Theo experiment 0

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