Inducing strong magnetism in Cr20Mn20Fe20Co20Ni20 high-entropy alloys by exploiting its anti-Invar property

The equiatomic high-entropy alloy Cr20Mn20Fe20Co20Ni20 high-entropy alloy has a valence-electron-concentration of 8 electrons/atom which is equivalent to that of Fe. The alloy being FCC is therefore electronically equivalent to FCC-Fe. We show through the thermal expansion properties that the alloy carries similar anti-Invar properties as FCC-Fe, but unlike FCC-Fe it is stable throughout its solid-state temperature-range. Therefore, by exploiting the anti-Invar property and expanding the lattice of the alloy by introducing interstitial carbon, we make Cr20Mn20Fe20Co20Ni20 ferromagnetic with a Curie temperature lying above room temperature.