Role of Magnetic Defects in Tuning Ground States of Magnetic Topological Insulators

被引：11

作者：

Islam, Farhan ^{[1
,2
]}

Lee, Yongbin ^{[1
]}

Pajerowski, Daniel M. M. ^{[3
]}

Oh, JinSu ^{[1
]}

Tian, Wei ^{[3
]}

Zhou, Lin ^{[1
,4
]}

Yan, Jiaqiang ^{[5
]}

Ke, Liqin ^{[1
]}

McQueeney, Robert J. J. ^{[1
,2
]}

Vaknin, David ^{[1
,2
]}

机构：

[1] Ames Natl Lab, Div Mat Sci & Engn, Ames, IA 50011 USA

[2] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA

[3] Oak Ridge Natl Lab, Neutron Scattering Div, Oak Ridge, TN 37831 USA

[4] Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA

[5] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

来源：

ADVANCED MATERIALS | 2023年 / 35卷 / 21期

关键词：

ferromagnetic correlation; localized dimer formation; magnetic inelastic neutron scattering; magnetic topological insulators;

D O I：

10.1002/adma.202209951

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Magnetic defects play an important, but poorly understood, role in magnetic topological insulators (TIs). For example, topological surface transport and bulk magnetic properties are controlled by magnetic defects in Bi2Se3-based dilute ferromagnetic (FM) TIs and MnBi2Te4 (MBT)-based antiferromagnetic (AFM) TIs. Despite its nascent ferromagnetism, the inelastic neutron scattering data show that a fraction of the Mn defects in Sb2Te3 form strong AFM dimer singlets within a quintuple block. The AFM superexchange coupling occurs via Mn-Te-Mn linear bonds and is identical to the AFM coupling between antisite defects and the FM Mn layer in MBT, establishing common interactions in the two materials classes. It is also found that the FM correlations in (Sb1-xMnx)(2)Te-3 are likely driven by magnetic defects in adjacent quintuple blocks across the van der Waals gap. In addition to providing answers to long-standing questions about the evolution of FM order in dilute TI, these results also show that the evolution of global magnetic order from AFM to FM in Sb-substituted MBT is controlled by defect engineering of the intrablock and interblock coupling.

引用

页数：8