Magnetostatic effect of the change in the shape of 180o domain walls near grain boundaries in plates of triaxial ferromagnets of the Fe-3% Si-alloy type

Sheiko L. M. 1Bagriytchuk A. S. Murashkinzeva T. N. 

1. Zaporizhzhe National University (ZNU), Zhukovsky 66, Zaporizhzhe +380612, Ukraine

Abstract

Grain boundaries (GBs) exert a substantial effect on the domain structure (DS) and magnetic properties of polycrystalline materials [1-3]. The role of such defects is especially large in the formation of structure and properties of nanomaterials and composites [4,5], in which the relative volumes of grain boundaries and interphase boundaries can exceed 20%. In this work, we report the results of a theoretical investigation into the main features of the spatial distribution of spontaneous magnetization Ms(r), the topology of magnetostatic fields Hm(r) near GBs, and the results of calculations of the shape z(x) of 180o DWs in plates of triaxial ferromagnets such as silicon iron (~3% Si) with a surface plane (011) in a demagnetized state (at He=0). It is shown that in the states of thermodynamic equilibrium Bloch domain walls can bend as a consequence of deviations Δθ(x) of the magnetic moments of atoms ma from the <100> easy axis under the effect of magnetic stray fields Hm generated by grain boundaries (the μ* - effect inside magnetic domains near grain boundaries). The magnitudes of the effects studied (the deviations Δθ(x) of the Ms vectors from the easy axes, the magnitudes of the flexures Δzbend of domain walls, the extensions of the macroscopic zones Δxbend characterized by inhomogeneous magnetization, as well as the maximum values of the strengths Hmx of the magnetostatic fields Hm near grain boundaries) increase with decreasing magnetocrystalline anisotropy constant and increasing period of the domain structure 2D.

[1] J.Goodenough, Phys. Rev. 1954. V.95. № 4. P. 917-932.

[2] A.Hubert, R.Schafer, Magnetic Domains: The Analysis of Magnetic Microstructures (Springer, Berlin, 1998. 696 p.).

[3] L.Sheiko, Gh.Brekharya, O.Kulyk, JMMM. 2000. V.215-216. P. 86-88.

[4] G.Herzer, JMMM. 1996.V.157-158, P.133-136.

[5] F.Mazaleyrat, L.K.Varga, JMMM. 2000. V.215-216. P. 253-259.

Related papers
  1. Calculation of magnetostatic energy Fm of periodic domain structures formed near grain boundaries in plates of triaxial ferromagnets of silicon iron type

Presentation: poster at E-MRS Fall Meeting 2005, Symposium B, by Sheiko M. Leonid
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-16 16:03
Revised:   2009-06-07 00:44
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