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

The layered van der Waals compounds ( MnBi 2 Te 4)( Bi 2 Te 3) were recently established as the first intrinsic magnetic topological insulators. We report a study on the epitaxial growth of ( MnBi 2 Te 4 ) m ( Bi 2 Te 3 ) n films based on the co-deposition of MnTe and Bi 2 Te 3 on BaF 2 (111) substrates. X-ray diffraction and scanning transmission electron microscopy evidence the formation of multilayers of stacked MnBi 2 Te 4 septuple layers and Bi 2 Te 3 quintuple layers with a predominance of MnBi 2 Te 4. 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 MnBi 2 Te 4 single crystals and confirm antiferromagnetic order in the films.