Influence of Nanocrystalline Structure on the Magnetic Propertiesof Wires and Microwires

The determining factors of the outstanding magnetic properties of the so-called nanocrystallinematerials are described. The discussion is based on results performed on wiresand microwire materials with general composition FeSiB(CuNb) and obtained by differentrapid solidification techniques. The evolution of magnetic properties (i.e., coercivity,magnetostriction) is correlated with the structural evolution associated to the correspondingheating parameters, experimentally determined by X-ray diffraction or differentialscanning calorimetry. Finally, a discussion is introduced on the important roleplayed by the structural nature of a two-phase system into the above-mentioned magneticproperties. A final analysis of some technological applications of devitrified magnetic wiresand microwires is presented.