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The interplay between magnetism and quantum effects has motivated several thermoelectric studies on iron‐telluride yet with little insight on the anomalous features in transport properties near magnetostructural transition temperature (≈70 K). A detailed investigation is carried out on Fe1.1Te by characterizing magnetic, heat capacity, galvanomagnetic, and thermoelectric transport properties to understand the electronic, magnetic, and structural origin of those anomalies. The magnetic susceptibility indicates a bicollinear stripe and short‐range ordering in the antiferromagnetic and paramagnetic domains, respectively. Hall conductivity and transverse magnetoresistance reveal a multicarrier transport impacted by spin fluctuations and magnons. Contributions from phonon‐drag and magnon‐drag are evaluated to understand the origin of the broad peak in antiferromagnetic thermopower. The peak at ≈50 K and the insignificant entropy contribution from the magnonic heat capacity support the phonon‐drag as the origin. The field‐dependent enhancement of thermal conductivity must be associated with field‐dependent spin‐phonon coupling modification. The field‐induced thermopower reduction can be attributed to the suppression of magnons or paramagnons, as evidenced by the magnetic susceptibility data. Above 70 K, the thermal conductivity drops sharply due to the structural change modifying phonon modes. Understanding these properties originated from the spin, and quantum effects are instrumental for designing high‐performance spin‐driven thermoelectrics.
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Giant effect of spin–lattice coupling on the thermal transport in two-dimensional ferromagnetic CrI 3
High performance thermal management is of great significance to the data security and working stability of magnetic devices with broad applications from sensing to data storage and spintronics, where there would exist coupling between the spin and phonon (lattice vibrations). However, the knowledge of the spin effect on thermal transport is lacking. Here, we report that the thermal conductivity of monolayer CrI 3 is more than two orders of magnitude enhanced by the spin–lattice coupling. Fundamental understanding is achieved by analyzing the coupling among electronic, magnetic and phononic properties based on the orbital projected electronic structure and spin density. The bond angles and atomic positions are substantially changed due to the spin–lattice coupling, making the structure more stiff and more symmetric, and lead to the weaker phonon anharmonicity, and thus the enhanced thermal conductivity. This study uncovers the giant effect of spin–lattice coupling on the thermal transport, which would deepen our understanding on thermal transport and shed light on future research of thermal transport in magnetic materials.
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- PAR ID:
- 10157812
- Date Published:
- Journal Name:
- Journal of Materials Chemistry C
- Volume:
- 8
- Issue:
- 10
- ISSN:
- 2050-7526
- Page Range / eLocation ID:
- 3520 to 3526
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/c9tc05928h
