Low-temperature hardening of coercivity of amorphous alloys

The temperature dependence of the coercivity was measured in Fe85-xCoxB15 a nd Co77B23 as-cast amorphous ribbons. A fast increase of the coercivity was found for T < 100 K. The temperature dependence of the susceptibility, pin ning field, saturation magnetostriction and saturation magnetisation was us ed to describe the temperature dependence of the coercivity. The hardening of the coercivity for low temperatures (T < 100 K) is well described by sho rt-range pinning mechanism, whereas for high temperatures, magnetostrictive interactions between internal stresses and the domain walls lead to a pinn ing effect. (C) 2001 Elsevier Science B.V. All rights reserved.