35 research outputs found
The local magnetic moments and hyperfine magnetic fields in disordered metal-metalloid alloys
The local magnetic moments and hyperfine magnetic fields (HFF) in the ordered
alloys Fe_{15}Sn and Fe_{15}Si are calculated with the first-principles
full-potential linear augmented plane wave (FP LAPW) method. The results are
compared with the experimental data on Fe-M (M=Si, Sn) disordered alloys at
small metalloid concentration. The relaxation of the lattice around the
impurity and its influence on the quantities under consideration are studied.
The mechanism of the local magnetic moment formation is described. It is proved
that the main distinction between these alloys is connected with the different
lattice parameters. Three contributions to the HFF are discussed: the
contributions of the core and valence electron polarization to the
Fermi-contact part, and the contibution from the orbital magnetic moment.Comment: 3 pages, 3 figures, submitted to Phys. Rev.
Structure peculiarities of cementite and their influence on the magnetic characteristics
The iron carbide is studied by the first-principle density functional
theory. It is shown that the crystal structure with the carbon disposition in a
prismatic environment has the lowest total energy and the highest energy of
magnetic anisotropy as compared to the structure with carbon in an octahedron
environment. This fact explains the behavior of the coercive force upon
annealing of the plastically deformed samples. The appearance of carbon atoms
in the octahedron environment can be revealed by Mossbauer experiment.Comment: 10 pages, 3 figures, 3 tables. submitted to Phys.Rev.