RESISTIVITY VARIATION NEAR THE CRITICAL-TEMPERATURE IN SOME NI-FE BASE AMORPHOUS ALLOYS

Accurate measurements of the electrical resistivity of three Ni80-xFexP14B6 alloys (with x=10, 20 and 30) were performed in the temperature interval 1.5-500 K. Resistivity (ρ) and dρ/dT behaviours near Tc for the alloys with different x values are mutually very different. In particular dρ dT variation near Tc for the alloys with x=10 and 20 is Ornstein-Zernicke like while for the alloy with x=30 is of more usual energy like type. A tentative explanation of this behaviour in terms of the influence of the percolation limit on the nature of the magnetic transition is offered. © 1979.