Structural evolution, site ordering and magnetic properties of tetragonal Mn6‐yGa2+y (0 ≤ y ≤ 1.64)

A D022-type super structure with a formula Mn6‐yGa2+y (0≤y≤1.64) is proposed to describe the structural evolution of tetragonal Mn3‐xGa (0≤x≤1.8) intermetallic compounds. Degree of site disorder is obtained based on the 2b-site Mn and 2a-site Ga disordering model. Neutron data refinement indicates that the structure transforms from a completely ordered state (y=0) to the 2a and 2b sites (Mn-Ga) disordered state (y>0.92) with increasing y. The ferrimagnetic ordering structure between Mn (4d) and Mn (2a/2b) has been established, with the magnetic moment retaining almost 2.2μB and ranging from −3.3μB (y→0) to −2.3μB (y→1.64), respectively.