2006 年 47 巻 7 号 p. 1728-1730
In this work, large values of magnetoimpedance from Fe74.5−xCuxNb1.5V1.5Si13.5B9 as-quenched ribbons is reported. With increasing Cu content, the magnetoimpedance first increases, undergoes a maximum value at x=3.5, and then drops at higher Cu contents. The magnetoimpedance ΔZ⁄Z0 for the Fe71Cu3.5Nb1.5V1.5Si13.5B9 (x=3.5) as-quenched ribbon reaches −31.3% under a field of H=7162 A/m at 1.2 MHz. The grain size of α-Fe(Si) for as-quenched Fe71Cu3.5Nb1.5V1.5Si13.5B9 (x=3.5) ribbon is estimated as 14–16 nm. Results show that nanocrystalline Fe-Cu-(Nb,V)-Si-B ribbons with giant magnetoimpedance can be prepared directly from the melt–spinning technique without annealing.