Martensitic and magnetic transformations of Ni56Fe17Ga27−xCox high-temperature ferromagnetic shape memory alloys

A phenomenon whereby both the martensitic transformation start temperature (Ms) and Curie temperature (Tc) of Ni56Fe17Ga27−xCox alloys increase while maintaining Tc > Af > Ms > 100 °C (where Af is the austenite finish temperature) with increasing Co content at the expense of Ga is reported. The martensitic structure of this alloy is 6 M, which is different from the common structure such as 7 and 5 M. The mechanical properties of the Ni56Fe17Ga27−xCox alloys are improved with increasing Co content.