Origin of the charge density wave state in BaFe$_2$Al$_9$
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arXiv
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| Auteurs principaux: | , , , , , , , , , |
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| Format: | Preprint |
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2024
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| _version_ | 1866916469947760640 |
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| author | Li, Yuping Liu, Mingfeng Li, Jiangxu Wang, Jiantao Lai, Junwen He, Dongchang Qiu, Ruizhi Sun, Yan Chen, Xing-Qiu Liu, Peitao |
| author_facet | Li, Yuping Liu, Mingfeng Li, Jiangxu Wang, Jiantao Lai, Junwen He, Dongchang Qiu, Ruizhi Sun, Yan Chen, Xing-Qiu Liu, Peitao |
| contents | Recently, a first-order phase transition associated with charge density wave (CDW) has been observed at low temperatures in intermetallic compound BaFe$_2$Al$_9$. However, this transition is absent in its isostructural sister compound BaCo$_2$Al$_9$. Consequently, an intriguing question arises as to the underlying factors that differentiate BaFe$_2$Al$_9$ from BaCo$_2$Al$_9$ and drive the CDW transition in BaFe$_2$Al$_9$. Here, we set out to address this question by conducting a comparative \emph{ab initio} study of the electronic structures, lattice dynamics, \textcolor{black}{and electron-phonon interactions} of their high-temperature phases. We find that both compounds are dynamically stable with similar phonon dispersions. The electronic structure calculations reveal that both compounds are nonmagnetic metals; however, they exhibit distinct band structures around the Fermi level. In particular, BaFe$_2$Al$_9$ exhibits a higher density of states at the Fermi level with dominant partially filled Fe-$3d$ states and a more intricate Fermi surface. This leads to an electronic instability of BaFe$_2$Al$_9$ toward the CDW transition, which is manifested by the diverged electronic susceptibility at the CDW wave vector $\mathbf{q}_{\rm CDW}$=(0.5, 0, 0.3), observable in both the real and imaginary parts. Conversely, BaCo$_2$Al$_9$ does not display such behavior, aligning well with experimental observations. Although the electron-phonon interactions in BaFe$_2$Al$_9$ surpass those in BaCo$_2$Al$_9$ by two orders of magnitude, the strength is relatively weak at the CDW wave vector, suggesting that the CDW in BaFe$_2$Al$_9$ is primarily driven by electronic factors. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2410_22734 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Origin of the charge density wave state in BaFe$_2$Al$_9$ Li, Yuping Liu, Mingfeng Li, Jiangxu Wang, Jiantao Lai, Junwen He, Dongchang Qiu, Ruizhi Sun, Yan Chen, Xing-Qiu Liu, Peitao Materials Science Recently, a first-order phase transition associated with charge density wave (CDW) has been observed at low temperatures in intermetallic compound BaFe$_2$Al$_9$. However, this transition is absent in its isostructural sister compound BaCo$_2$Al$_9$. Consequently, an intriguing question arises as to the underlying factors that differentiate BaFe$_2$Al$_9$ from BaCo$_2$Al$_9$ and drive the CDW transition in BaFe$_2$Al$_9$. Here, we set out to address this question by conducting a comparative \emph{ab initio} study of the electronic structures, lattice dynamics, \textcolor{black}{and electron-phonon interactions} of their high-temperature phases. We find that both compounds are dynamically stable with similar phonon dispersions. The electronic structure calculations reveal that both compounds are nonmagnetic metals; however, they exhibit distinct band structures around the Fermi level. In particular, BaFe$_2$Al$_9$ exhibits a higher density of states at the Fermi level with dominant partially filled Fe-$3d$ states and a more intricate Fermi surface. This leads to an electronic instability of BaFe$_2$Al$_9$ toward the CDW transition, which is manifested by the diverged electronic susceptibility at the CDW wave vector $\mathbf{q}_{\rm CDW}$=(0.5, 0, 0.3), observable in both the real and imaginary parts. Conversely, BaCo$_2$Al$_9$ does not display such behavior, aligning well with experimental observations. Although the electron-phonon interactions in BaFe$_2$Al$_9$ surpass those in BaCo$_2$Al$_9$ by two orders of magnitude, the strength is relatively weak at the CDW wave vector, suggesting that the CDW in BaFe$_2$Al$_9$ is primarily driven by electronic factors. |
| title | Origin of the charge density wave state in BaFe$_2$Al$_9$ |
| topic | Materials Science |
| url | https://arxiv.org/abs/2410.22734 |