Physical properties of nearly zero magnetostriction Co-rich glass-coated amorphous microwires

Magnetic and mechanical properties of Go-rich amorphous microwires of nominal compositions (Co1-xMnx)(75)Si-10 B-15 (0.08 < x < 0.11) and Co56.5Fe6.5Ni10B16Si11 with nearly zero magnetostriction constant have been studied. Drastic changes of the hysteresis loop with the decrease of x from rectangular to flat shape were observed at x < 0.1, while the Co56.5Fe6.5Ni10B16Si11 microwire showed rectangular hysteresis loops. Compositions with x greater than or equal to 0.1 have small but positive magnetostriction constant while negative lambda(s) values have been observed at x less than or equal to 0.09, indicating rectangular character of the hysteresis loop in samples with nearly zero and even for small negative lambda(S). External stress dependence of switching field, H*, showed an increase of H* with sigma for samples with x = 0.11 and a decrease of H* with sigma for x = 0.1. Besides, microwires of the same composition but with different dimensions showed different H*(sigma) dependencies.