Epitaxial ferromagnetic τ-MnAl films on GaAs

TLDR: In this article, the growth of epitaxial τ-MnAl ferromagnetic films on GaAs substrates by molecular beam epitaxy (MBE) was reported and it was shown that the τ-phase films grow with the c axis of the tetragonal unit cell normal to the substrate surface.

Abstract: We report the growth of epitaxial τ‐MnAl ferromagnetic films on GaAs substrates by molecular beam epitaxy (MBE). Reflection high‐energy electron diffraction and x‐ray diffraction show that the τ‐phase films grow with the c axis of the tetragonal unit cell normal to the {100}GaAs substrate surface. In the bulk, τ‐MnAl is a metastable ferromagnetic phase with uniaxial magnetocrystalline anisotropy. The large hysteresis observed in the Hall resistance versus applied magnetic field suggests that the easy magnetization direction is indeed parallel to the c axis in the MBE‐grown films. The growth of these ferromagnetic films with perpendicular magnetization on compound semiconductor substrates creates the possibility of novel devices that combine magnetic memory and magneto‐optic functions with semiconductor electronics and photonics.