MAGNETO-IMPEDANCE OF AMORPHOUS (FEV)(80)B-20 RIBBONS IN A LONGITUDINAL-FIELD

Amorphous Fe80-xVxB20 ribbons (with x = 0-16 at% V) were cast by rapid quenching. In this report we studied the response of the impedance Z of these as-cast glasses to an external magnetic field. The frequency f of the driving current was varied from 10 kHz to 5 MHz. When f is fi xed, a longitudinal field along the long side of the sample was applie d to examine the resistive R(H) and reactive X(H) plots. The magneto-i mpedance (MI) is defined as Delta R/R = [R(0)/R(H-s)] - 1 and Delta X/ X = [X(0)/X(H-s)] - 1, where H-s is the minimum field to saturate the sample. The spectra of Delta R/R and Delta X/X showed that Delta R/R i ncreases, while Delta X/X decreases with f. At room temperature the la rgest MI is about 20% (sensitivity 3%/Oe) from Fe75.2V4.8B20 sample. ( C) 1998 Elsevier Science B.V. All rights reserved.