Gradual phase transition from ferromagnetic tetragonal to antiferromagnetic cubic states in MnxGa (1.80 <= x <= 3.03) thin films

Abstract

The structural, magnetic, and electronic properties of MnxGa thin films are investigated as varying the Mn composition (1.80 <= x <= 3.03). The variation of x in MnxGa films dramatically changes the crystal structure as well as the magnetic properties. With increasing x, we observe the gradual phase transition from a ferromagnetic tetragonal state to an antiferromagnetic cubic state. The structural characterization reveals that the D0(22) tetragonal structure of Mn2Ga is slowly transformed to the L1(2) cubic structure of Mn3Ga. Two phases coexist around x = 2.4. The magnetization is systematically reduced as x increases, ending to an antiferromagnetic state of cubic Mn3Ga, and the electrical resistivity increases with x. Such highly tunable magnetic and electronic properties in MnxGa phase simply by the variation of the Mn/Ga ratio provide advantages to be used for spintronic device applications. (C) 2019 Elsevier B.V. All rights reserved.