Molecular Beam Epitaxy Growth of Ferromagnetic MnSb on InGaSb: Characterization of Orientation, Interfaces, and Magnetic Properties*

Ferromagnets compatible with high spin-orbit coupling III-V semiconductors (InAs, InSb) can be used for spin injection, breaking the spin degeneracy in 1D nanowire systems with the potential for creating Majorana Zero Modes.¹ The transition metal monopnictide MnSb is a hexagonal ferromagnet with a high Curie temperature and is the most Sb-rich binary phase, suggesting high thermodynamic stability in contact with InGaSb. Although MnSb has been grown on III-V substrates, here a new growth orientation has been observed with the c-axis perpendicular to the growth plane. In-situ reflection high-energy electron diffraction and ex-situ high resolution X-ray diffraction were used to determine that the films are oriented as (10-10)[0001][-12-10] MnSb||(001)[1-10][110] InGaSb. Superconducting quantum interference device (SQUID) magnetometry was used to determine that the magnetic easy axis lies along the c axis of the MnSb, while the hard axis lies in the basal plane. Transmission electron microscopy confirmed the growth techniques presented allow us to grow MnSb on a high spin-orbit coupling III-V ternary semiconductor with a relatively abrupt interface, in comparison to MnSb films grown on InGaAs.<sup>2

1</sup>Nano Lett. 20, 3232 (2020).

²J. Cryst. Growth, 498, 391 (2018).