Dependence of Magnetic and Magnetoimpedance Properties of Samples of Amorphous Fe-Based Alloys on Their Shape. Influence of Glass Shell Thickness in the Case of Microwires

Amorphous magnetic metal alloys are a rather new class of materials compared to crystalline ones. They differ significantly from crystalline materials in their structure and physical and magnetic properties. The amorphous state of matter is a state in which there is no long-range order in the arrangement of atoms. The lack of long-range order often leads to changes in physical properties that are difficult or impossible to obtain in a solid with a crystalline structure. One important factor is the extremely small value of magnetocrystalline anisotropy, which leads to an increase in the contributions of magnetoelastic anisotropy and shape anisotropy. In the presented work, a comparative analysis of the magnetic properties of three types of samples prepared from amorphous Fe77.5Si12.5B10 alloy (ribbons, thick wires, and glass-shell microwires) has been carried out. It is found that the impedance characteristics of all the samples are quite small, although they depend on the type of the sample. For composite samples (glass-covered microwire), the magnetic properties strongly depend on both the thickness of the metallic core and the ratio of the total thickness of the microwire to the thickness of the metallic core. The obtained experimental results are presented in the form of graphical dependences.