The Layer-Inserting Growth of Antiferromagnetic Topological Insulator MnBi₂Te₄ Based on Symmetry and Its X-ray Photoelectron Spectroscopy

The antiferromagnetic topological insulator has attracted lots of attention recently, as its intrinsic magnetism and topological property make it a potential material to realize the quantum anomalous Hall effect at relative high temperature. Until now, only MnBi2Te4 is predicted and grown successfully. The other MB2T4-family materials predicted (MB2T4: M = transition metal or rare earth element, B = Bi or Sb, T = Te, Se, or S) with not only antiferromagnetic topological property but also rich and exotic topological quantum states and dynamically stable (or metastable) structure have not been realized on experiment completely. Here, MnBi2Te4 single crystals have been grown successfully by us. It shows typical antiferromagnetic character with Neel temperature of 24.5 K and a spin-flop transition at H approximate to 35,000 Oe, 1.8 K. In order to obtain the other members of MB2T4-family materials, it is necessary to understand the growth mode of MnBi2Te4. Its growth mode may be the layer-inserting growth mode based on symmetry, which is supported by our X-ray photoelectron spectroscopy (XPS) result, as the intrinsic chemical states of Mn and Te of MnBi2Te4 are the same with those of inserting material alpha-MnTe. Understanding the growth mode of MnBi2Te4 can help us to grow the other members of MB2T4-family materials.