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The well-known method of planar flow casting has been used for preparation single- and tri-layered ribbons of the same composition to attain ribbon thickness significantly different. The aim was to suppress potentially undesired surface effects of chemical or topological differences between ribbon surfaces/volume. The prepared ribbons’ composition was Co47Fe21Mo6.5B21Si4.5 and the samples were investigated for structural, chemical and magnetic properties in amorphous (as-cast) and crystalline state. The average thickness was ∼55 µm for the trilayer and ∼14.5 µm for the monolayer, thus the thickness ratio was somewhat more than 3:1. The composition chosen targeted low saturation magnetostriction and nanocrystallization improved soft magnetic properties more namely for trilayer. The reduction of large surface/volume ratio, that enables shrinking surfaces to squeeze efficiently the small volume of single ribbon, proved effective indeed.

Alloys of composition (Fe-Co)83(Sn-P)5B12 have been prepared by planar flow casting method in air with substitution Co = 0; 5; 10 at. % for Fe and substitution P = 2 at. % for Sn. All as-cast ribbons were amorphous and submitted to chemical and thermal analyses, scanning and transmission electron microscopy and magnetic measurements. Hysteresis loops of strips after nanocrystallization at 380 and 400 °C for 30 min changed their shape – the saturation magnetization increased for Co containing alloys Js = 1.74–1.80 T. The off-axis component of magnetic anisotropy decreased significantly due to the annealing. Coercivity in this case considerably increased due to the growth of grain size and crystalline volume fraction. The samples annealed at 350 °C disclosed a relaxed state with changes in microstructure and achieved very good soft-magnetic properties namely for P substituted alloys.

Si-poor Fe 74 Nb 3 Cu 1 Si 8 B 14− x P x , ( x =0, 3) nanocrystalline ribbon-form alloys often form surfaces, which exert in-plane force on underlying ribbon interior when nanocrystallized in even modest presence of oxygen. Mostly unwanted hard-ribbon-axis magnetic anisotropy is standard result. Essential sources of the surface-caused stress have been sought and influence of P instead of B substitution on this effect was studied too. Preferred surface crystallization (PSC) was found to be the major reason. However P substitution suppresses PSC and promotes Fe-oxide formation, which eases the stress, softens the surfaces and provides different annealing evolution of surface properties.