Evolution of Phonon Transport Across Structural Phase Transitions in MgAgSb
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arXiv
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| Autori principali: | , , , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2026
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| _version_ | 1866910053612650496 |
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| author | Shang, Luman Wu, Yu Liu, Yufan Zeng, Shuming Tang, Gang Liu, Chenhan |
| author_facet | Shang, Luman Wu, Yu Liu, Yufan Zeng, Shuming Tang, Gang Liu, Chenhan |
| contents | MgAgSb, a promising thermoelectric material, undergoes reversible phase transitions that drastically alter its thermal transport behavior. Using first-principles calculations, we systematically investigate the lattice thermal conductivity ($κ_L$) of its three phases: $α$, $β$, and $γ$, revealing a progressive increase following $α< β< γ$. This trend originates from distinct scattering mechanisms. Four-phonon scattering substantially suppresses the particle-like conductivity ($κ_p$) in the $β$ and $γ$ phases, while electron-phonon scattering provides a minor additional reduction. In contrast, the wave-like conductivity ($κ_c$) from coherent phonon tunneling is highest in the complex $α$ phase, contributing up to 44\% of $κ_L$. Notably, the temperature dependence of $κ_L$ differs fundamentally between phases: in $β$, the weak $κ_p$ variation arises from a decreasing Grüneisen parameter with temperature; in $α$, the strong rise in $κ_c$ with temperature counteracts the decay of $κ_p$. Our findings establish a comprehensive picture of thermal transport in MgAgSb, highlighting the phase-dependent interplay between particle-like and wave-like phonon contributions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_14213 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Evolution of Phonon Transport Across Structural Phase Transitions in MgAgSb Shang, Luman Wu, Yu Liu, Yufan Zeng, Shuming Tang, Gang Liu, Chenhan Materials Science MgAgSb, a promising thermoelectric material, undergoes reversible phase transitions that drastically alter its thermal transport behavior. Using first-principles calculations, we systematically investigate the lattice thermal conductivity ($κ_L$) of its three phases: $α$, $β$, and $γ$, revealing a progressive increase following $α< β< γ$. This trend originates from distinct scattering mechanisms. Four-phonon scattering substantially suppresses the particle-like conductivity ($κ_p$) in the $β$ and $γ$ phases, while electron-phonon scattering provides a minor additional reduction. In contrast, the wave-like conductivity ($κ_c$) from coherent phonon tunneling is highest in the complex $α$ phase, contributing up to 44\% of $κ_L$. Notably, the temperature dependence of $κ_L$ differs fundamentally between phases: in $β$, the weak $κ_p$ variation arises from a decreasing Grüneisen parameter with temperature; in $α$, the strong rise in $κ_c$ with temperature counteracts the decay of $κ_p$. Our findings establish a comprehensive picture of thermal transport in MgAgSb, highlighting the phase-dependent interplay between particle-like and wave-like phonon contributions. |
| title | Evolution of Phonon Transport Across Structural Phase Transitions in MgAgSb |
| topic | Materials Science |
| url | https://arxiv.org/abs/2603.14213 |