Thermal Annealing is a simple and powerful tool to improve the crystallinity in general or promote the functionality for peculiar purposes, ultimately leading to metastable states with lower energy. We report the annealing effect focusing primarily on the structural and magnetic properties of two different Mn₃Ga thin films. One is the D0₂₂ tetragonal ferrimagnetic phase Mn₃Ga, and the other is the disordered-L1₂ cubic antiferromagnetic phase Mn₃Ga. They were grown by RF/DC magnetron sputtering method on MgO substrate. After deposition, the thin films were annealed at various temperatures (200, 300, 400, 500, and 600 °C) and Ar pressures (10⁻³, 10⁻¹, and 10³ Torr). We find that the most effective annealing temperature is 400 °C and their properties are the most changed by the Ar pressure. The D0₂₂ tetragonal ferrimagnetic phase Mn₃Ga is transformed to L1₀ cubic ferromagnetic phase MnGa due to the Mn diffusion, whereas the disordered-L1₂ cubic antiferromagnetic phase Mn₃Ga is converted to the ordered-L1₂ cubic ferrimagnetic phase within the Mn₃Ga phase. We discuss the structural and magnetic properties of each phase to unveil the mechanism of both phase transitions. These results will provide a better understanding of the magnetic phase transition with the structural phase transition in the composition-sensitive Heusler thin films.

热退火是一种简单而功能强大的工具，可以总体上提高结晶度或提高其功能性，从而最终以较低的能量产生亚稳态。我们报告的退火效应主要集中在两种不同的Mn ₃ Ga薄膜的结构和磁性。一个是D0 ₂₂四方铁磁相的Mn ₃ Ga和另一种是无序-L1 ₂立方反铁磁相的Mn ₃镓。它们是由RF / DC磁控管的MgO基板上溅射法生长。在沉积之后，薄膜，在各种温度和Ar压力（10退火（200，300，400，500 600℃，）^-3，10 ^-1，和10³托）。我们发现最有效的退火温度为400°C，并且其性能受Ar压力影响最大。由于Mn的扩散，D0 ₂₂四方亚铁磁性相Mn ₃ Ga转变为L1 ₀立方铁磁性相MnGa，而无序的L1 ₂立方反铁磁性相Mn ₃ Ga被转变成Mn内的有序L1 ₂立方亚铁磁性相₃镓相。我们讨论了每个相的结构和磁性，以揭示两个相变的机理。这些结果将提供对组成敏感的赫斯勒薄膜中的磁性相变与结构相变的更好的理解。