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.

We have studied the domain wall longitudinal propagation and its dynamics under the influence of transverse magnetic field in thin magnetic wires. A different behavior was observed for strong and weak transverse fields. In weak transverse field $H_{\text{t}}$ , the domain wall dynamics depends on the direction of $H_{\text{t}}$ . Transverse field applied in one direction increases the Walker limit and shifts the existence of transverse domain wall to higher axial field. Transverse magnetic field applied in opposite direction decreases the Walker limit and favors vortex domain wall even at low fields. Different behavior was obtained in strong transverse field which speeds up the domain wall velocity to its saturation value of 9 km/s independently on the orientation of transverse field.

The propagation of domain walls in magnetic microwires has been investigated over the temperature range $77\text{–}373\mathrm{K}$. Very high domain wall velocities, up to $1800\mathrm{m}∕\mathrm{s}$, were observed, in combination with enhanced domain wall mobilities at high temperature. In contrast, the domain wall mobility is low at low temperature, though the wires still exhibit relatively high domain wall velocities $(\sim 600\mathrm{m}∕\mathrm{s})$. A mechanism for obtaining high wall velocities, based on a negative critical propagation field, is described.

A new smart concrete aggregate design as a candidate for applications in structural health monitoring (SHM) of critical elements in civil infrastructure is proposed. The cement-based stress/strain sensor was developed by utilizing the stress/strain sensing properties of a magnetic microwire embedded in cement-based composite (MMCC). This is a contact-less type sensor that measures variations of magnetic properties resulting from stress variations. Sensors made of these materials can be designed to satisfy the specific demand for an economic way to monitor concrete infrastructure health. For this purpose, we embedded a thin magnetic microwire in the core of a cement-based cylinder, which was inserted into the concrete specimen under study as an extra aggregate. The experimental results show that the embedded MMCC sensor is capable of measuring internal compressive stress around the range of 1–30 MPa. Two stress sensing properties of the embedded sensor under uniaxial compression were studied: the peak amplitude and peak position of magnetic switching field. The sensitivity values for the amplitude and position within the measured range were 5 mV/MPa and 2.5 µs/MPa, respectively.

The damping mechanisms affecting the motion of a single domain wall were studied in a thin bistable magnetic wire. It was found that the overall damping is frequency and temperature dependent through the locally induced anisotropy via structural relaxation. This phenomenon can increase the overall damping by one order of magnitude and enables an effective tailoring of the domain wall dynamics according to required application.

We have studied the evolution of domain wall dynamics during the devitrification of amorphous and nanocrystalline ${\text{Fe}}_{73.5}{\text{Cu}}_1{\text{Nb}}_3{\text{Si}}_{11.5}{\text{B}}_{11}$ microwires. Depending on the annealing temperature range, three different regimes in the domain wall dynamics can be considered for these materials. Annealing below the Curie temperature, $T_{\text{c}}$, of the alloy leads to the stabilization of the domain structure and a strong temperature dependence of the domain wall dynamic parameters. However, annealing above $T_{\text{c}}$ leads to a destabilization of domain patterns and a decrease in the domain wall damping in one order of magnitude. Finally, annealing above the crystallization temperature, $T_{\text{x}}$, leads to the appearance of the nanocrystalline state that is structurally very stable. In this case, the domain wall velocity is very fast due to the lack of magnetic anisotropy and extremely stable with the temperature.