Giant anisotropic in-plane thermal conduction induced by Anomalous phonons in pentagonal PdSe2
- Henan Polytechnic University, Jiaozuo (China); Beijing Institute of Technology (China)
- Beijing Institute of Technology (China)
- Univ. of California, Riverside, CA (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Henan Polytechnic University, Jiaozuo (China)
In two-dimensional materials, different atomic stacking induces anisotropic atomic interactions and phonon dispersions, leading to the anisotropy of in-plane thermal transport. In this work, we report an exceptional case in layered pentagonal PdSe2, where the bonding, force constants, and lattice constants are nearly-equal along the in-plane crystallographic axis directions, while the thermal conductivity is surprisingly much greater along b-axis than along a-axis with a ratio up to 1.8. Such strong anisotropy is not only unexpected in in-plane uniform structured materials, but also 2 comparable to the record high in-plane anisotropic thermal conductivity in the nonuniform structured material reported to date (the ratio is ~2.0 in TiS3). By combining the inelastic X-ray scattering measurement and the first-principles calculations, we attribute such high anisotropy to the low-energy phonons along a-axis, particularly their lower group velocities and “avoided-crossing” behavior. The different buckling structures between a- (zigzag-type) and b-axis (flat-type) are mainly responsible for such unique phonon dynamics properties of PdSe2. This finding helps to discover materials with high anisotropic in-plane thermal conductivity in uniform structures and reveals new physics of anisotropy of in-plane thermal conduction. Due to the unique features in structure and thermal transport properties, PdSe2 may serve as a new platform for designing novel devices to route heat flow precisely at the nanoscale.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- Beijing Natural Science Foundation; National Key Research and Development Program of China; National Natural Science Foundation of China (NSFC); USDOE Office of Science (SC)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1846427
- Journal Information:
- Materials Today Physics, Journal Name: Materials Today Physics Vol. 22; ISSN 2542-5293
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electronic, transport, and optical properties of bulk and mono-layer PdSe{sub 2}
Anisotropic Phonon Response of Few-Layer PdSe2 under Uniaxial Strain