Recent advances in technology involving magnetic materials require development of novel advanced magnetic materials with improved magnetic and magneto-transport properties and with reduced dimensionality. Therefore magnetic materials with outstanding magnetic characteristics and reduced dimensionality have recently gained much attention. Among these magnetic materials a family of thin wires with reduced geometrical dimensions (of order of 1–30 μm in diameter) have gained importance within the last few years. These thin wires combine excellent soft magnetic properties (with coercivities up to 4 A/m) with attractive magneto-transport properties (Giant Magneto-impedance effect, GMI, Giant Magneto-resistance effect, GMR) and an unusual re-magnetization process in positive magnetostriction compositions exhibiting quite fast domain wall propagation. In this paper we overview the magnetic and magneto-transport properties of these microwires that make them suitable for microsensor applications.

Here, we present experimental evidence for the very fast domain wall in microwires that can reach wall-motion velocity approaching $18.5\mathrm{km}∕\mathrm{s}$, which is much higher than the sound velocity in the magnetic wires. We show that the domain wall speed can be adjusted by counterbalancing between the longitudinal magnetic anisotropy leading to small damping and the strong transversal anisotropy.

The phenomena of low-field hysteresis of the magnetoimpedance (MI) in zero-magnetostrictive amorphous wires are studied theoretically and experimentally. We developed a mathematical model for magnetization reversal and impedance field dependence. The presented model considers the low-field hysteresis and the effect of circular bias magnetic field. It is demonstrated that the hysteresis originates from a nonzero angle $\alpha$ between the anisotropy easy axis and transversal plane. The bias field, which is produced by current running through the wire, considerably affects the MI dependence making it anhysteretic and highly asymmetric. The validity of the model is confirmed by the experiments. The main characteristics of the studied amorphous wire such as anisotropy field $H_A$, angle between the anisotropy easy axis with the transversal direction $\alpha$, and Gilbert damping constant ${\alpha }_G$ were obtained from the experiment in accordance with the presented model.