Magnetic charge and hyperfine splitting in hydrogen

The large spatial size of magnetic charges (or dyons) and parity considerations are used to show that in models of the proton based on dyons the hyperfine splitting must be due to the magnetic moment produced by the electric charge. The contributions of the magnetic monopoles cancel, otherwise the proton would have a large electric dipole moment.     

Proton-polarizability contribution to the hyperfine splitting in hydrogen

The contribution of the proton polarizability to the hyperfine splitting in hydrogen is evaluated on the basis of modern experimental and theoretical results on the proton polarized structure functions. The value of this correction is 1.4 ppm.     

Temperature dependence of the magnetic hyperfine splitting of metastable iron-amalgam

The temperature dependence of the magnetic hyperfine field of a metastable iron-mercury alloy has been measured. The Mössbauer spectrum obtained at 12 K can be fitted with two magnetically split components with hyperfine fields of 39.7 and 36.0 T. With increasing temperature the hyperfine fields decrease much more rapidly than that of α-Fe. The temperature dependence is in accordance with the Bloch law up to 220 K.     

Shell model analysis of the magnetic hyperfine splitting in muonic thallium

The magnetic hyperfine splitting of the ground and first excited state in muonic²⁰³Tl and²⁰⁵Tl is calculated on the basis of the shell model with configuration mixing. Fair agreement with the recently measured ground state splitting is found.     

Magnetic hyperfine splitting in superparamagnetic particles in external magnetic fields

The magnetic hyperfine splitting in Mössbauer spectra of superparamagnetic particles, induced by an external magnetic field, has been calculated. Numerical results have been obtained both for isolated particles with a finite value of the magnetic anisotropy energy constant and for strongly interacting particles. Moreover, analytical approximations are derived. The theoretical results are compared with results of experimental studies of supported α-Fe particles and magnetic particles in ferrofluids.     

Effect of hydrogen on the hyperfine magnetic field in crystalline Zr-Fe alloys

This paper deals with room temperature⁵⁷Fe Mössbauer studies performed on crystalline Zr_1–y Fe _y and Zr_1–y Fe _y H _x (0.05y0.5) alloys. For hydrogenated alloys, the transition from parato ferromagnetic behaviour is observed aty = 0.25, i.e. a considerably lower concentration of iron compared to uncharged alloys. It seems to be not only attributable to ZrFe₂ formation. Apart from ZrFe₂, a relatively intensive and quite different than the ZrFe₂ contribution to theP(B) distribution has been observed for hydrogen charged alloys with only 25 at.% Fe. It is linked to the origin of the additional magnetic component due to hydrogen absorption in which Fe has less than 6 Fe nearest neighbours.     

Quantized magnetic flux through the ground-state orbit of the hydrogen atom

We have investigated the spin-dependent quantized magnetic fluxes through the ground-state electronic orbit of the hydrogen atom. We show that the corresponding fluxes are (1/2)Φ₀ for the spin-up case and (3/2)Φ ₀ for the spin-down case, respectively, where Φ₀ = hc/e is the flux quantum. Using the energy-flux proportionality, we also show that the spin-up case (where the electron spin is antiparallel to the proton spin, resulting in zero total spin) is the spin-dependent ground state of the hydrogen atom. The present result helps to understand the spin flip-flop in excitonic transitions in nanostructures.     

Nuclear shielding and magnetic hyperfine structure of hydrogen cyanide

A millimeter-wave molecular beam maser has been used to resolve the magnetic hyperfine structure of hydrogen cyanide. The spin-rotation interaction constants have been measured for the three nuclei ¹⁴N, ¹³C, and H. The paramagnetic nuclear shielding factors have been calculated for the three nuclear sites. The spin-rotation constants for ¹⁴N in H¹²C¹⁴N, for H in H¹²C¹⁴N and for ¹³C in D¹³C¹⁴N are + 10.4 kHz, −3.7 kHz, and +15.0 kHz, respectively. The respective paramagnetic shielding factors are −408.98 × 10⁻⁶, −73.40 × 10⁻⁶, and −249.52 × 10⁻⁶.     

Proposed measurement of the ground-state hyperfine structure of antihydrogen

The ASACUSA collaboration at CERN-AD has recently submitted a proposal to measure the hyperfine splitting of the ground state of antihydrogen in an atomic beam line. The spectrometer will consist of two sextupoles for spin selection and analysis, and a microwave cavity to flip the spin of the antihydrogen atoms. Numerical simulations show that such an experiment is feasible if ~200 antihydrogen atoms per second can be produced in the ground state, and that an accuracy of better than 10^–7 can be reached. This measurement will be a precise test of the CPT invariance. B. Juhász serves as one of the authors of this article on behalf of the ASACUSA collaboration.     

The splitting of hyperfine lines of57Fe nuclei in RF magnetic field

It is shown experimentally, that for Moessbauer nuclei affected by the radio-frequency (RF) magnetic field of sufficient intensity at frequencies corresponding to NMR, splitting of Zeeman sublevels of nuclei and changes in Moessbauer spectral structure occurs. Depending on the frequency of alternating field each spectral line is splitinto (2·Ig,e +1) comporients, Ig,e-being the nuclear spin of ground and excited state, respectively. The intensity of RF components and the energy gap between them are extremely sensitive to the frequency and the intensity of the RF magnetic field.     

Anomalous magnetic behaviour of zinc and chromium ferrites without any hyperfine splitting

Two groups of ferrite namely zinc ferrite and chromium ferrite were synthesized by citrate precursor route in the size range of 8 to 35 nm. We have studied the structural and magnetic behaviour of these ferrites using X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and Mössbauer spectroscopic techniques. Our studies show that the nanocrystalline ferrites interact with the hand magnet strongly and give large magnetization in the VSM measurement. The maximum magnetization in the samples sensitively depends on the particle size of synthesized ferrites. We observed as large as 28 Am²/kg of magnetization in the zinc ferrite nanoparticles while that in chromium ferrite is around 11 Am²/kg. In spite of the large magnetization in the zinc ferrite nanoparticles we did not observe any hyperfine splitting even down to 12 K of temperature. Similar behaviour is also observed for chromium ferrite down to 16 K.     

Electron self-energy in the presence of a magnetic field: hyperfine splitting and g factor

A high-precision numerical calculation is reported for the self-energy correction to the hyperfine splitting and to the bound-electron g factor in hydrogenlike ions with low nuclear charge numbers. The binding nuclear Coulomb field is treated to all orders, and the nonperturbative remainder beyond the known Zalpha-expansion coefficients is determined. For the 3He+ ion, the nonperturbative remainder yields a contribution of -450 Hz to the normalized difference of the 1S and 2S hyperfine-structure intervals, to be compared with the experimental uncertainty of 71 Hz and with the theoretical error of 50 Hz due to other contributions. In the case of the g factor, the calculation provides the most stringent test of equivalence of the perturbative and nonperturbative approaches reported so far in the bound-state QED calculations.     

Origin of the residual acceptor ground-state splitting in silicon

The residual ground-state splitting of acceptors in high-quality silicon has been studied intensely by different experimental techniques for several decades. Recently, photoluminescence studies of isotopically pure silicon revealed the ground-state splitting to result from the random distribution of isotopes in natural silicon. Here we present a new model that explains these surprising experimental results, and discuss the implications for acceptor ground-state splittings observed in other isotopically mixed semiconductors, as well as for the acceptor ground state in semiconductor alloys.     

The symmetry properties and collinearity of the magnetogyric,hyperfine splitting and magnetic susceptibility tensors

The symmetry properties of g and A cannot be elicited using invariance properties, due to their special nature, and are found using the properties of a Kramers doublet. It is shown that the collinearity of g and A depends on the molecule having at least C ₂ with σ _v or C ₂′ symmetry elements. The symmetry properties of x are found from those of g. The conditions for collinearity of the tensors and the consequences of non-collinearity are discussed, with examples.     

Measurement of the 8S hyperfine splitting in cesium

The Cs 8S level hfs splitting δ₈ has been measured. The experimental value δ₈ = (900 ± 60) MHz is in good agreement with both other experimental results and theoretical predictions.     

ESR investigations on hydrogen-induced hyperfine splitting features in ZnO

Low temperature X-band electron spin resonance measurements (ESR) were performed on as-grown and post-hydrogenated zinc oxide (ZnO) single crystals. As-grown ZnO exhibits a single strong line at g=1.957$g=1.957$ that was identified as hydrogen. In contrast, post-hydrogenated ZnO shows a distinctly different ESR spectrum. Besides the intensification of the hydrogen donor line, hydrogenation triggers the observation of additional hyperfine lines. They are attributed to manganese (Mn) impurities probably introduced from the growth process. From the ESR data a Mn concentration of 6×10¹³ cm⁻³ was estimated.