Kinetic arrest of the ferromagnetic state in Mn$$_3$$GaC and Ni$$_2$$MnGa composite mixtures

Abstract

AbstractThe kinetics of the ferromagnetic to antiferromagnetic transition in Mn$$_3$$ 3 GaC can be arrested and its magnetic properties can be tuned by mixing a small amount ($$\sim $$ ∼ 10%) of Heusler Ni$$_2$$ 2 MnGa to Mn$$_3$$ 3 GaC. A detailed study of magnetic properties of composite mixtures of Mn$$_3$$ 3 GaC and Ni$$_2$$ 2 MnGa with different antiperovskite to Heusler ratio, reveals that the ferromagnetic Ni$$_2$$ 2 MnGa polarizes magnetic spins of the antiperovskite phase by creating a magnetic strain field in its vicinity. The Heusler phase acts as a defect centre whose influence on the magnetic properties of the majority antiperovskite phase progressively diminishes, creating a distribution of transition temperatures. Such strong interaction between the two phases of the mixture allows for tunability and control over the properties of such magneto-structurally transforming materials.