MAGNETO-IMPEDANCE OF SOME NONZERO MAGNETOSTRICTIVE AMORPHOUS RIBBONS

The magneto-impedance (MI) of three commercial metallic glasses, 2605S 2 (lambda(s) = 2.7 x 10(-5)), VAC4040 (lambda(s) = 8 x 10(-6)) and VAC 6030 (lambda(s) < 3 x 10(-7)) has been measured, where lambda(s) is th e magnetostriction. The MI is defined as Delta R/R = [R(O)/R(H-s)] - 1 and Delta X/X = [X(O)/X(H-s)] - 1, where H-s is the saturating field along the long side of the sample, R is the resistance, and X is the r eactance. At lower frequencies, the MI is resistance-limited, while at higher frequencies it is inductance-limited, and a crossover occurs a t a characteristic frequency f(0) in between. f(0) was found for the t hree materials. Also, it is found that (1) the MI decreases as lambda( s), increases from 10(-7) to 10(-5), and (2) field-annealing below the Curie temperature does not improve MI performance in the non-zero mag netostrictive glasses.