Site preference and magnetism of Fe3−xCrxAl0.5Si0.5

► Cr locates preferentially in B sublattice in DO3-type structure of Fe3Al0.5Si0.5. ► Lattice parameter of Fe3−xCrxAl0.5Si0.5 does not change with Cr concentration. ► Magnetic moments of Fe(A,C), Fe(B) and Cr(B) decrease linearly with Cr content.