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 . High quality single crystals of Zn-doped MnBi 2 Te 4 were synthesized successfully by using self-flux method. The red shift of Raman frequencies with increasing Zn content indicates the substitution of Zn for Mn. The magnetic transition field of MnBi 2 Te 4 decreases with Zn doping significantly. Non-magnetic element doping is found to be an effective way to modulate the magnetic interaction of MnBi 2 Te 4 . • High quality crystals of Zn - doped MnBi 2 Te 4 were synthesized successfully by using self - flux method. • All single crystals synthesized were characterized by Raman spectroscopy. • Non-magnetic element Zn doping dilutes the magnetic interaction of MnBi 2 Te 4 effectively. • The magnetic transition field of Mn 1- x Zn x Bi 2 Te 4 decreases significantly with increasing Zn concentration.