Low-temperature hardening of coercivity of amorphous alloys

Abstract

The temperature dependence of the coercivity was measured in Fe 85− x Co x B 15 and Co 77B 23 as-cast amorphous ribbons. A fast increase of the coercivity was found for T<100 K. The temperature dependence of the susceptibility, pinning field, saturation magnetostriction and saturation magnetisation was used to describe the temperature dependence of the coercivity. The hardening of the coercivity for low temperatures ( T<100 K) is well described by short-range pinning mechanism, whereas for high temperatures, magnetostrictive interactions between internal stresses and the domain walls lead to a pinning effect.