Relationship among Structure, Disorder, Magnetism, and Band Topology in the MnSb2Te4·(Sb2Te3)n Family

The interplay between topology and magnetism induces various exotic quantum phenomena, with magnetic topological insulators (MTIs) serving as a prominent example due to their ability to host the quantum anomalous Hall effect (QAHE). However, the realization of the QAHE at a higher temperature approaching the magnetic transition temperature remains a significant challenge, primarily due to the scarcity of suitable material platforms and our limited understanding of the intricate relationships among band topology, magnetism, and defects. Here, we report a comprehensive investigation of MnSb₂Te₄·(Sb₂Te₃)_n (n = 0-5) single crystals, including the discovery of the novel MnSb₈Te₁₃ pure phase. Experimental measurements confirm that MnSb₈Te₁₃ exhibits ferromagnetism and features topologically nontrivial electronic structures, characterized by a Dirac point located farther from the conduction band and a possible larger bulk gap compared to that of MnBi₂Te₄·(Bi₂Te₃)_n (n = 0-3). Moreover, we systematically analyze the relationship among structure, magnetism, topology, and disorder within the Mn(Sb, Bi)₂Te₄·((Sb, Bi)₂Te₃)_n family. This work will shed light on the exploration of potential platforms capable of achieving QAHE near the magnetic transition temperature, offering new directions for advancing topological quantum materials.