Strain-induced coercivity enhancement in Mn51Al46C3 flakes prepared by surfactant-assisted ball milling

•We report the preparation of Mn51Al46C3 flakes employing different processing routes.•A correlation between the coercivity and internal strain has been established.•The variation in the lattice parameters is attributed to the internal strain.•The defects and the strained areas act as the source of domain wall pinning.

A correlation between the coercivity and internal strain has been established for as-milled τ-phase Mn51Al46C3 flakes prepared by surfactant-assisted ball milling (SABM). The variation in the lattice parameters is attributed to the internal strain induced by the continuous high speed collision from the balls during the SABM process. A high coercivity up to 266.2 kA/m was accompanied by a relatively large residual strain, due to the domain wall pinning effect of the defects and the associated strained areas. The effect of strain on the coercivity of MnAl flakes provides a good approach for achieving highly tunable coercivity for the magnetic materials.