Crystal growth and magnetic evolution of antiferromagnetic topological insulator Zn-doped MnBi2Te4

As the first intrinsic magnetic topological insulator , MnBi 2 Te 4 has provided a material platform for the realization of various novel physical phenomena arising from the interaction between magnetism and band topology. Here, transition element Zn - doped MnBi 2 Te 4 crystals of millimeter size, synthesized by using self-flux method, are reported. With increasing Zn content, the hexagonal lattice shrinks, and the Raman frequencies show a red shift. All samples undergo a transition from A - type antiferromagnetic (A - AFM) to canted antiferromagnetic (CAFM) to ferromagnetic (FM) under magnetic field . The antiferromagnetic ordering temperature slightly increases from 24.2 K for MnBi 2 Te 4 to 25.2 K for Mn 0.75 Zn 0.25 Bi 2 Te 4 . The transition field from AFM to CAFM decreases from 3.4 T for x  = 0–3.07 T for x  = 0.25. Isothermal magnetization data suggest that the single - ion anisotropy of Mn 2+ decrease and the interlayer magnetic interaction increase slightly due to the diluted magnetic ions and unit cell shrinkage. Samples Mn 0.9 Zn 0.1 Bi 2 Te 4 and Mn 0.8 Zn 0.2 Bi 2 Te 4 show metallic conduction with a cusplike anomaly at around T N  ≈ 24 K, corresponding to a long - range antiferromagnetic (AFM) transition. The increase of T N and decrease of transition field ( H c S F ) upon Zn doping, make it possible to manipulate magnetic and electrical properties in topological insulators by non - magnetic element substitution, which is of great significance for further application in quantum information storage and spintronics .