Influence of glass coating thickness and metallic core diameter on GMI effect of glass-coated Co_(68)Fe_(4.5)Si_(13.5)B_(14) amorphous microwires

摘要

Influences of the size factors (glass coating thickness and metallic core diameter) of microwires on GMI effects of the glass-coated Co_(68)Fe_(4.5)Si_(13.5)B_(14) amorphous microwires were investigated. The results indicated that the GMI effect of the microwires with the same glass coating thickness or the same metallic core diameter was initially increased to a peak and then decreased with an increase in the diameter or the thickness. The glass coating thickness and the metallic core diameter corresponding to the maximum GMI varied with metallic core diameter and glass thickness, respectively. The GMI effect of the microwires with the same geometric size varied remarkably under different cooling rates. Such effect was ascribed to the microstructural changes of the metallic core wire under different cooling rates. The influence of the glass coating thickness on the GMI effect of the microwire was attributed to the synthetical actions of crystallization enthalpy (degree of disorder) and the internal stress.