Molecular beam epitaxy of antiferromagnetic (MnBi2Te4)(Bi2Te3) thin films on BaF2 (111)

Abstract

The layered van der Waals compounds (MnBi2Te4)(Bi2Te3) were recently established as the first intrinsic magnetic topological insulators. We report a study on the epitaxial growth of (MnBi2Te4)m(Bi2Te3)n films based on the co-deposition of MnTe and Bi2Te3 on BaF2 (111) substrates. X-ray diffraction and scanning transmission electron microscopy evidence the formation of multilayers of stacked MnBi2Te4 septuple layers and Bi2Te3 quintuple layers with a predominance of MnBi2Te4. The elemental composition and morphology of the films is further characterized by x-ray photoemission spectroscopy and atomic force microscopy. X-ray magnetic circular and linear dichroism spectra are comparable to those obtained for MnBi2Te4 single crystals and confirm antiferromagnetic order in the films.