Resistivity of Two Amorphous Fe-Ni Based Alloys Near Their Ferromagnetic Transitions

Abstract

For almost all amorphous magnetic systems studied so far, the critical indices for the phase transition at the Curie point are non-Heisenberg like (β ≃ 0.4, γ ≃ 1.6). Via scaling relations this gives the specific heat index α - 0.4, indicating that the singularity at Tc is considerably reduced. To confirm this α value, a direct measurement of α would be valuable. This is possible via resistance measurements, since dρ/dT has the same critical behaviour as CP.