Disorder effect of 3d transition elements in DO3 Heusler alloy Mn2FeAl

DO3 disorder is essential to elucidate the properties of many 3d group Heusler alloys, especially Mn2-based alloys. The DO3 disorder for Mn2FeAl, corresponding to the exchange between Mn and Fe atoms, is difficult to distinguish with the normal x-ray diffraction instrument because of similar atomic scattering factors for Mn and Fe atoms. However, via the observation of magnetic behavior, the DO3 disorder has been observed indirectly. Many pieces of evidence show the existence of DO3 disorder in our samples. A qualitative method is employed to clarify the degree of DO3 disorder for Mn2FeAl alloys with the results of first-principles calculations, and this method can be applied to many Mn2-based alloys. In addition, full ordering occupation of Al atoms has been observed and Mn2FeAl without any disorder could be prepared hopefully for further work.