Magnetic Properties of Multi-Layered Metallic Ribbons

The method of planar flow casting has been used for preparation of single-, bi- and tri-layered ribbons of the two different or the same composition to attain multi-layered ribbons suitable for an application. Prepared bilayer was composed of positively and negatively magnetostrictive layers Fe77.5Si7.5B15/Co72.5Si12.5B15. Other aim was to suppress potentially undesired surface effects of differences between ribbon surfaces and volume. We prepared the ribbons with composition Co47Fe21Mo6.5B21Si4.5 as single layer and trilayer with the thickness ratio more than 3:1. Structural, chemical and magnetic properties in amorphous (as-cast) and crystalline state were investigated. The composition was chosen to obtain low saturation magnetostriction. Nanocrystallization improved soft magnetic properties namely for trilayer. Work proved that reduction of large surface/volume ratio enables to reduce undesired effects of shrinking surfaces that squeeze the small volume of a single ribbon more efficiently.