2004 Volume 45 Issue 9 Pages 2794-2796
With increasing Cu content x in Fe74.5−xCuxNb3Si13.5B9 as cast ribbons, an enhancement of magnetoimpedance can be observed. The magnetoimpedance (Z(H) − Z(0))/Z(0) for Fe72Cu2.5Nb3Si13.5B9 as cast ribbon reaches −35% under a dc field H = 7162 A/m at a frequency ƒ = 1 MHz. The longitudinal magnetoimpedance effect in Fe74.5−xCuxNb3Si13.5B9 as cast ribbons is connected with the variation of transverse permeability. The grain size of α-Fe(Si) in Fe72Cu2.5Nb3Si13.5B9 as cast ribbon was estimated as about 7—10 nm. This revealed that soft magnetic nanocrystalline materials with giant magnetoimpedance effect can be obtained directly from the melt - spinning technique without additional annealing processes.