High spin polarization in epitaxial films of ferrimagnetic Mn3Ga

Ferrimagnetic Mn3Ga exhibits a unique combination of low saturation magnetization (M-s = 0.11 MAm-1) and high perpendicular anisotropy with a uniaxial anisotropy constant of K-u = 0.89 MJm(-3). Epitaxial c-axis films exhibit spin polarization as high as 58%, measured using point-contact Andreev reflection. These epitaxial films will be able to support thermally stable sub-10-nm bits for spin-transfer torque memories.