The paper presents an iron-57 Mössbauer spectral study of RFe11.5Ta0.5, with R=Tb, Dy, Ho, Er, Lu, and an evaluation of the different contributions to the hyperfine magnetic fields. The Mössbauer spectra have been analyzed with a model that considers both the distribution of the tantalum atoms in the near-neighbor environment of the iron atoms and the relative orientation of the hyperfine field...

A first testing ground for QED in the combined presence of a strong Coulomb field and a strong magnetic field is provided by the precise measurement of the hyperfine structure splitting of hydrogenlike 209Bi. We present a complete calculation of the one-loop self-energy correction to the first-order hyperfine interaction for various nuclear charges. In the low-Z regime we almost perfectly agree...

X-band EPR spectra have been recorded at room temperature for V 0 2 + impurity in single crystals of t r is-Guanadiniumhexafluoroaluminate, [C(NH2)3]3A1F6 . 1 9 F super hyperfine structure has been observed on the 5 V hyperfine lines. V 0 2 + replaces Al 3 + to form an effective VOF5 complex. There are three possible V O bond orientations in the A1F6 octahedron but with differing occupancy fact...

The ferredoxin from parsley has been purified to a high degree. The protein contains 2.o iron atoms per molecule, has an iron to labile sulfide ratio of unity and consumes 9 moles of mercurial, leading to calculated molecular weights of 1o8oo, 1o75o and 1o96o, respectively. These compare well with the results of amino acid analysis which gave a molecular weight of 1o66o. The dithionite-reduced ...