Arrott-Noakes Plots for Magnetization of Some 3d-Transition Metals and Alloys in High Magnetic Fields

Magnetizations of pure Ni, 10 at% Cu–Ni, 10 at% Co–Ni, 46 at% Fe–Ni and amorphous 16 at% B–Fe alloys have been measured in static magnetic fields up to 100 kOe in the temperature range around the Curie points. The relation between magnetization M , field H and temperature T is satisfactorily fitted to an equation ( H / M ) 0.75 = a ( T - T c )+ b M 2.5 for all the alloys investigated, where a and b are constant parameters and T c is the Curie temperature. Accordingly, isotherms of the Arrott-Noakes plots, M 2.5 vs ( H / M ) 0.75 , are parallel straight lines.