Strain- and Temperature-Modulated Growth of Mn3Ga Films

Antiferromagnetic (AF) and ferrimagnetic (FiM) thin films have burgeoning significance in memory and computing applications due to their robustness and ultrafast and energy-efficient switching dynamics. Mn3Ga features a multitude of spin orders that can be meticulously controlled with stoichiometry, temperature, and strain modulations. In this work, we have carefully designed three suitable stacks of Mn3Ga thin films on MgO (111), STO (111) and STO (111)/Ta substrates deposited across varying substrate temperatures up to 500°C. The delicate interplay of strain and temperature tuning is examined by characterizing their magnetic, crystallographic, and morphological properties. The FiM tetragonal τ-Mn3Ga and AF hexagonal ε-Mn3Ga phases display relatively low saturation magnetizations of 10–60 and ≤ 20 kA/m, respectively. No preferential in-plane or out-of-plane magnetic anisotropy is observed for both τ- and ε-Mn3Ga phases. Critically, we observed that the STO strain-regulated τ-phase is stabilized over a wider temperature window and provides more compact, uniformly dispersed grains with average grain size of 100 nm. This work establishes a sturdy methodology in understanding Mn3Ga thin film growth for eventual AF- and FiM-based memory and computing applications.