J. Phys. IV France 07 (1997) C1-449-C1-450
The Effect of Diamagnetic Defect in YIG on the Hyperfine Field AnisotropyJ. Kohout1, H. Stepankova1, J. Englich1, P. Novak2 and H. Lütgemeier3
1 Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 180 00 Prague 8, Czech Republic
2 Institute of Physics, Academy of Sciences, Cukrovarnicka 10, 160 00 Prague 6, Czech Republic
3 IFF, KFA Jülich, 52425, Germany
The dependence of 57Fe NMR spectra in YIG on the external magnetic field direction was measured at 4.2K. The high purity single crystal of a spherical form was used. The external magnetic field of 0.75T was applied in several directions lying in (110) plane. The satellite structure of the spectra caused by an antisite defects Y(a) (Y3+ ion on the a site, nominally occupied by Fe3+ ion) enabled us to study the effect of a nonmagnetic impurity on the 57Fe hyperfine field anisotropy. The tensors of hyperfine interaction for 57Fe in d- sites with the nearest and next nearest Y(a) defect were obtained from NMR data. The results were confronted with the predictions of the independent bond model.
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