acta physica slovaca

Acta Physica Slovaca 62, No.5, 411 – 518 (2012) (108 pages)


Rastislav Varga
    Institute of Physics, Faculty of Science, UPJS Košice, Park Angelinum 9 SK-04 154 Košice, Slovakia

Full text: ::pdf :: (Received 31 March 2013, accepted 20 May 2013, in final form 4 June 2013)

Abstract: Glass-coated microwires are very interesting materials for theoretical study as well as for practical applications. Having positive magnetostriction, their domain structure consists of single axially magnetized domain and magnetization process runs through Large Barkhausen jump of a single domain wall along entire microwire. This gives us possibility to study a single domain wall propagation on large scales (few cm). As a result of their complex anisotropy distributon, the glass coated microwires exhibit very fast domain wall propagation, sometimes faster then sound speed. The domain wall dynamics can be very effectively modified by different anisotropies introduced in the wire by magnetic field, mechanical stress, thermal treatment, etc... In such a way, domain wall dynamics with the high domain wall velocity that is independent on magnetic field can be achieved. Stability of domain wall dynamics can be enhanced by using nanocrystalline compositions of microwire that combines low anisotropy of amorphous alloys with high structural stability of crystalline materials. On the other hand, sensitivity of domain wall dynamics on external parameters can be employed in the sensoric applications. The switching field at which the single domain wal starts to propagate is strongly sensitive to the temperature, mechanical stress, frequency of applied magnetic field etc... Knowing the physical origin of such sensitivies allows us to construct miniaturized multifunctional sensor that can even be embedded into the material structure.

DOI: 10.2478/v10155-012-0002-5

PACS: 75.60.Ej, 75.60.Jk
Keywords: Magnetic microwires, Domain wall dynamics, Switching field, Mag- netic anisotropy, Magnetic bistability, Nanocrystalline materials
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