Magnetic and Magnetotransport Studies of MBE-Grown Thin Films of the Antiferromagnetic Axion Insulator Candidate EuIn₂As₂

EuIn₂As₂ is an intrinsic antiferromagnetic topological insulator predicted to host the axion insulator state[1]. While previous studies on this material have focused on bulk single crystals, thin films are required to realize its predicted topological edge and surface states. We have successfully grown EuIn₂As₂ thin films on sapphire and yttrium aluminum garnet (YAG) substrates using molecular beam epitaxy. The films exhibit in-plane magnetic easy axis and a Néel temperature close to 17 K, with a spin-flop transition near 0.25 T consistent with bulk behavior [2,3]. On YAG, which offers a better lattice match, we obtain c-axis–oriented EuIn₂As₂ films confirmed by X-ray diffraction and energy-dispersive spectroscopy, with a lattice constant Å in agreement with bulk crystals. This talk will discuss the thickness dependence of the magnetic and magnetotransport properties of EuIn₂As₂ thin films and the impact of substrate choice on these properties.

[1] Y. Xu et al. Phys. Rev. Lett. 122, 256402 (2019)

[2] Y. Zhang Phys. Rev. B 101, 205126 (2020)

[3] M. Abdul Karim et al. Phys. Rev. Mater. 7, 104202 (2023)