Room-Temperature Ferromagnetism, Perpendicular Anisotropy, and Reverse Magnetostriction in 2D MnGaN*

MnGaN-2D has been discovered as an ultimately-thin (2D) DMS material showing 300 K ferromagnetism as demonstrated using spin-polarized scanning tunneling microscopy and confirmed by density functional theory revealing highly spin-split and spin-polarized manganese states.[1] SQUID magnetometry confirms these results and finds a high spin-polarization of ∼79% at room temperature and perpendicular magnetic anisotropy.[2] Spin-orbit coupling is included in the first-principles theoretical calculations, which indicate either in-plane or out-of-plane anisotropy, depending on the type of strain. Clear evidence for both compressive and tensile local lattice strains is also found by detailed analysis of atomic resolution STM images. Furthermore, scanning tunneling spectroscopy finds fluctuations in the electronic position of the filled states manganese peak, which is also found to depend on lattice strain in the theoretical calculations, thus indicating a connection between electronic states and magnetic anisotropy.

[1] Yingqiao Ma et al., Nano Letters, Vol. 18, p. 158 (2018)
[2] Yingqiao Ma et al., Physical Review Materials, Vol. 4, p. 064006 (2020)