THE CHANGE IN THE TEMPERATURE-COEFFICIENT OF RESISTIVITY WITH MN ADDITION IN FE-RICH AND CO-RICH AMORPHOUS-ALLOYS

Abstract

Electrical resistivity studies have been carried out on a-Co80-x-yFexMnyB12Si8 alloys for 10 less-than-or-equal-to x less-than-or-equal-to 70 and y=0,4,8. It has been found that the decrease of temperature coefficients of resistivity (TCR) with Mn substitution is significantly more in Fe-rich alloys than in Co-rich alloys. A T2 term is not found in Co-rich alloys even up to the addition of 8 at. % of Mn. Although Fe-rich alloys show a T2 dependence for 8 at. % of Mn, a second minimum is not observed. In the absence of Mn, the substitution of Fe for Co does not decrease the TCR while in the presence of Mn, the substitution of Fe does decrease the TCR.