Effect of the Ni content on the thermal and magnetic properties of Fe–Ni–Co alloys

In this study, the influence of the Ni content on the phase transformations of FeNiCo alloys was evaluated by analyzing seven different alloys with Fe-x%at.Ni-10%at.Co composition, in which x = 30, 24.5, 20, 15, 10, 5, and 0. These alloys were initially annealed and then studied by different experimental techniques. The results showed that the Ni concentration plays an important role in the magnetic transition temperature of the FeNiCo alloys, changing the magnetic and structural transition temperatures and promoting a magnetic hysteresis as high as 500 K. From these results, it was possible to propose a scheme for phase transformation of the Fe-Ni-Co alloys with 10%at.Co and content of nickel lower than 30%at.