The formation of the magnetic moments in disordered binary alloys of metal-metalloid type

Physico-Technical Institute, Ural Branch, Russian Academy of Sciences, 132 Kirov Street, SU-426001 Izhevsk, Russian Federation
Journal of Magnetism and Magnetic Materials (Impact Factor: 1.97). 11/1992; 117(1-2):87-92. DOI: 10.1016/0304-8853(92)90296-Z


The s-d model of disordered binary alloy with the Hubbard electron interaction is considered in the paper. The dependence of the local magnetic moment on the number of nonmagnetic atoms in the nearest neighborhood is received as a result of the solution of the self-consistent equation for the local magnetic moment. It is shown that the model proposed describes qualitatively the experimental data on the disordered binary substitution alloys of the metal-metalloid type and justifies the possibility of the phenomenological description of the local magnetic moments by modified Jaccarino-Walker models.

4 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: For non-ordered Fe alloys with concentration x>45 at.% of Al and xSn>50 at.% of Sn the dependence of magnetic parameters on the concentration, temperature and applied magnetic field are not characteristic of ferromagnets. Data [1-4] on the magnetic behavior of thin amorphous Fe-Sn films, being the closest in properties to the disordered nanocrystalline alloys, indicates that at xSn> 60 at.% Sn the ground magnetic state is of spin glass (SG), and in the interval of x=55-60 at.% Sn one may assume the coexistence of ferromagnetism (F) and SG. As far as the Fe-Al system is concerned, it is impossible to draw a conclusion on the peculiarities of the magnetic structure of higher AI concentration disordered alloys from magnetic measurements data alone where only the average magnetic moment per Fe atom [5,6] is registered. The magnetic state [7] of the disordered Fe60AU40 alloy was also determined as spin-glass. A considerable difference in the metalloid concentration of the vanishing average magnetic moment and the average hyperfine field, and the failure of saturation in the magnetization curves in the high external magnetic fields up to 5T (for Fe-Al alloys according to [6] even up to 15 T) can be regarded as the experimental signs of non-ferromagnetic behavior in high- concentration Fe-AI and Fe-Sn alloys. Concurrently, for these alloys there are no observed conventional signs for the spin-glass state such as the shifted about Happl=0 hysteresis loop or true temperature hysteresis in the magnetization curves. Thus, the magnetic structure of disordered nanocrystalline Fe alloys with Al and Sn needs to be specified.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have measured the concentration dependence of the average magnetic moment per Fe atom m¯Fe(x) in microcrystalline and amorphous Fe-P alloys obtained over a wide concentration range using electrochemical deposition. The model of local magnetic moments has been used to described m¯Fe(x). On the basis of this model the effects of phosphorus on the value m¯Fe are explained in terms of the parameters of the local environment of the Fe atom.
    Journal of Magnetism and Magnetic Materials 02/1994; 130(1-3):44-50. DOI:10.1016/0304-8853(94)90655-6 · 1.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The amorphous Fe78P22 alloy obtained by mechanical grinding was studied by X-ray analysis, Mössbauer spectroscopy and magnetic measurements. The measured values of the average hyperfine magnetic field H, mean magnetic moment per Fe atom mFe and Curie temperature Tc agree with those obtained earlier for electrodeposited and then ground samples and are in good qualitative agreement with the model describing macroscopic characteristics through the parameters of local environment but essentially disagree with the literature data for the samples obtained by rapidly quenching and only by electrochemical deposition.
    Journal of Magnetism and Magnetic Materials 06/1999; 195(3):601-604. DOI:10.1016/S0304-8853(99)00175-4 · 1.97 Impact Factor
Show more