Epitaxial D019-Mn3Ga thin films grown on the paramagnetic and diamagnetic MgO (111) substrate

50 nm-thick D0₁₉-Mn₃Ga epitaxial thin films were grown on MgO (111) substrates by rf-magnetron sputtering. Structural characterization demonstrated the single crystalline nature of the films grown at 400 and 500 °C, while those grown at 600 °C show an epitaxial mosaic-like growth together with the crystallization of the tetragonal D0₂₂ phase. The magnetic measurements evidenced the presence of diamagnetic and paramagnetic contributions due to the substrate, with the paramagnetic contribution probably due to magnetic impurities with concentration below 1 % atomic. We removed those contributions in both the magnetization-magnetic field and magnetization-temperature curves. After that correction, the magnetic loops of the D0₁₉-Mn₃Ga thin films were decomposed in antiferromagnetic and ferromagnetic components, employing the Brillouin function, the latest arising from the canting of the magnetic moment of the Mn atoms and the distortion of the kagome spin structure, of the D0₁₉ phase, at the boundaries between single crystalline domains as well as the ferrimagnetic contribution of the D0₂₂ clusters.