Distribution of magnetic dipole fields in amorphous ferromagnetic and speromagnetic alloys and in crystalline and amorphous spin glasses

Abstract

For binary alloys with only one sort of magnetic atoms we have calculated, by means of computer simulations, the distribution of magnetic dipole fields at regular lattice sites and suitably defined interstitial sites for the magnetic ground state of amorphous ferromagnetic and speromagnetic alloys and crystalline and amorphous spin glasses. Thereby we have considered spatially random arrangements of atoms and have neglected all magnetic correlations in the case of speromagnets and spin glasses. We have derived symmetric and isotropic distribution functions, which are fairly well described by Gaussian distributions for large concentrations of magnetic atoms only. The distribution functions are characterized by their second moments, which are important for the discussion of NMR and μ⁺ SR relaxation rates in these materials.