Tuning magnetism and band topology through antisite defects in Sb-doped MnBi4Te7

Unconventional pressure-driven metamagnetic transitions in topological van der Waals magnets

“…1 (a). As a consequence of the competition between the "standard" Mn1-Mn1 AFM interlayer superexchange interaction assisted by hopping to the Bi/Sb/Te atoms and the Mn3mediated Mn1-Mn1 FM interlayer exchange interaction, this series has comparable FM and AFM energies (43). The x = 0 member is an A-type antiferromagnet with the spins ferromagnetically aligned in the ab plane but antiferromagnetically aligned along the c axis.…”

“…Particularly, the as-grown MnBi 4 Te 7 and MnBi 6 Te 10 may become FM under certain growth conditions (26,39), indicating close proximity of FM and AFM energy scales in this family. Chemical doping has been used to tune the magnetism in MBT (40)(41)(42)(43)(44). The effect can be best seen in Mn(Bi 1−x Sb x ) 4 Te 7 , where a doping-dependent metamagnetic transition between the FM and AFM states is observed upon cooling (43).…”

“…Chemical doping has been used to tune the magnetism in MBT (40)(41)(42)(43)(44). The effect can be best seen in Mn(Bi 1−x Sb x ) 4 Te 7 , where a doping-dependent metamagnetic transition between the FM and AFM states is observed upon cooling (43). However, the vacancies and antisite disorder introduced by doping are uncontrollable, making the delineation of the effects of the three major magnetic interactions challenging.…”

Growth, characterization and Chern insulator state in MnBi$_2$Te$_4$ via the chemical vapor transport method

“…Antisites result in additional Mn sublattices in MBT. While the effect is relatively weak in MnBi 2 Te 4 , it is exaggerated in MnSb 2 Te 4 41 , Sb-doped MnBi 2 Te 4 39 and Sbdoped MnBi 4 Te 7 42 since sizable amount of Mn Sb antisites are introduced when Sb atoms are present in the lattice, leading to ferrimagnetic ground states. From the aspect of band topology, large amount of Mn Sb antisites can be detrimental to non-trivial band topology in MBT 41,42 .…”

“…While the effect is relatively weak in MnBi 2 Te 4 , it is exaggerated in MnSb 2 Te 4 41 , Sb-doped MnBi 2 Te 4 39 and Sbdoped MnBi 4 Te 7 42 since sizable amount of Mn Sb antisites are introduced when Sb atoms are present in the lattice, leading to ferrimagnetic ground states. From the aspect of band topology, large amount of Mn Sb antisites can be detrimental to non-trivial band topology in MBT 41,42 . Because the QAHE is proposed theoretically on the ideal MnBi 2 Te 4 structure, the defects which have caused the aforementioned complications may hinder the exploration of QAHE in MBT.…”