Ferromagnetism at room temperature in Cr-doped polycrystalline Mn2GaC MAX phase thin films

Abstract

Magnetic MAX phases are nanolaminated compounds where competing interactions within and between laminae shape their complex magnetic ordering. The resulting low magnetization and ordering temperature has limited their use in practice but the search for ferromagnetism at room temperature has been ongoing. Here, we show that a strong ferromagnetic response can be obtained at room temperature in the MAX phase Mn2GaC by partially substituting Mn by Cr. Polycrystalline (0001) textured (Mn1−xCrx)2GaC films are obtained on SiO2/Si (001) substrates for 0≤x≤0.29 and films with 0.06≤x≤0.29 show a ferromagnetic response at room temperature. The magnetization peaks at Ms=420±20 kA/m for x=0.12. The films with x>0.06 have an in-plane magnetic anisotropy and are isotropic within the film plane. The results show that the room temperature ferromagnetic response in Cr-doped Mn2GaC is not restricted to single-crystal films which facilitates its use in device applications and bulk magnets.