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Giant thermal switching in ferromagnetic VSe2 with programmable switching temperature
Chao Wu1,2, Yunshan Zhao3, Gang Zhang4
1Micro- and Nano-scale Thermal Measurement and Thermal Management Laboratory, School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, 210023, P. R. China. chenhanliu@njnu.edu.cn.
Nanoscale Horizons
|December 9, 2022
Summary
This study reveals a giant thermal switching ratio of 12 in 2D VSe2, enabling efficient heat energy management. This discovery advances understanding of thermal conductivity in magnetic materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Physics
Background:
- Active thermal conductivity modulation is crucial for efficient heat energy management in applications like thermoelectrics.
- Two-dimensional (2D) materials offer unique properties for advanced thermal applications.
Purpose of the Study:
- To report a giant thermal switching ratio in monolayer 2H-VSe2.
- To investigate the underlying mechanisms of thermal switching in 2D ferromagnets.
- To explore thermal switching in bulk 2H-VSe2.
Main Methods:
- First-principles calculations were employed to investigate thermal conductivity.
- Analysis focused on phonon bandgaps, phonon-phonon scattering, and phonon anharmonicity.
Main Results:
- A giant thermal switching ratio of 12 was achieved in monolayer 2H-VSe2 above room temperature.
- Ferromagnetic ordering induced a phonon bandgap, significantly suppressing phonon-phonon scattering.
- Bulk 2H-VSe2 exhibited a thermal switching ratio of 9.2 at its magnetic transition temperature.
Conclusions:
- Monolayer 2H-VSe2 demonstrates significant potential for advanced thermal management applications.
- Phonon bandgap engineering via ferromagnetic ordering is a key mechanism for high thermal switching.
- This research provides new insights into heat energy transport and control in 2D magnetic materials.
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