Delicate Ferromagnetism in MnBi6Te10
Chenhui Yan1, Yanglin Zhu2, Leixin Miao3
1Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States.
Nano Letters
|October 31, 2022
Summary
Defects in MnBi6Te10 create tunable magnetic orders, crucial for topological quantum phenomena. This discovery offers a path for defect-engineering novel topological quantum phases.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Tailoring magnetic orders in topological insulators is key for topological quantum phenomena.
- A major challenge is finding materials with defect-tunable magnetism and nontrivial topology.
Purpose of the Study:
- To investigate disorder-enabled, tunable magnetic ground states in MnBi6Te10.
- To understand the role of atomic defects in magnetic and topological properties.
Main Methods:
- Magnetization measurements
- Angle-resolved photoemission spectroscopy (ARPES)
- Transmission electron microscopy (TEM)
Main Results:
- Disorder-tuned magnetic ground states were observed in MnBi6Te10.
- A 15 meV energy gap at the Dirac point was found in the ferromagnetic phase.
- Antiferromagnetic MnBi6Te10 showed gapless topological surface states.
- Significant Mn vacancies and migration were detected in the ferromagnetic phase.
Conclusions:
- Atomic defects, specifically Mn vacancies and migration, enable tunable magnetic topological orders.
- A conceptual framework explains how defects cooperatively alter magnetic ground state energies.
- This research provides a route for nanoscale defect-engineering of topological quantum phases.
More Related Videos
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.2K
07:42Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
2.8K
Related Concept Videos
01:31Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
03:02Colors and Magnetism
12.2K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.2K
02:42Valence Bond Theory
9.1K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
9.1K
01:26Diamagnetism
2.5K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.5K
01:30Paramagnetism
2.6K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.6K
01:18Other Unique Bacteria
63
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic...
63