Crystalline and transport characteristics of ferrimagnetic and antiferromagnetic phases in Mn₃Ga films

The Mn3Ga material is a promising candidate for memory and computing devices owing to its rich crystalline structures of tunable ferrimagnetic and collinear and non-collinear antiferromagnetic phases. In particular, Mn3Ga with non-collinear antiferromagnetic order exhibits giant anomalous and topological Hall conductivities and is a potential material platform for hosting spin-related quantum phenomena. In this study, we demonstrate Mn3Ga films grown on thermally oxidized Si substrates, with and without the T-a buffer, under different deposition temperatures (T-s). With increasing T-s, the dominant crystalline structure across all Mn3Ga films evolves from a cubic to hybrid tetragonal and hexagonal texture, wherein the crystalline orientation of spins endows the films with in-plane magnetic anisotropy. For T-a/Mn3Ga and Mn3Ga films grown under high T-s, the inhomogeneity in surface energy of the buffer layer results in a non-uniform granular film in the former. Notably, the Mn3Ga films of hexagonal texture exhibit topological Hall signatures. The density functional theory calculations on the hexagonal Mn3Ga phase corroborated with the experimental magnetic, structural, and transport properties. These findings establish an important platform for tailoring Mn3Ga films toward multifunctional applications.(c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).