Kurt, H.;Rode, K.; Stamenov, P.; Venkatesan, M.;Lau, Y.-C.; Fonda, E.; Coey, J.M.D.
Cubic Mn 2 Ga Thin Films: Crossing the Spin Gap with Ruthenium
Phys. Rev. Lett. 112 (2014), 027201
Cubic Mn 2 Ga films with the half-Heusler C1 b structure are grown on V (001) epitaxial films. The phase is a soft ferrimagnet, with Curie temperature T C 1⁄4 225 K and magnetization M s 1⁄4 280 kA m −1 , equiv- alent to 1.65 μ B per formula. Adding ruthenium leads to an increase of T C up to 550 K in cubic Mn 2 Ru x Ga films with x 1⁄4 0.33 and a collapse of the net magnetization. The anomalous Hall effect changes sign at x 1⁄4 0.5, where the sign of the magnetization changes and the magnetic easy direction flips from in plane to perpendicular to the film. The Mn 2 Ru 0.5 Ga compound with a valence electron count of 21 is identified as a zero-moment ferrimagnet with high spin polarization, which shows evidence of half-metallicity