Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability
Abstract Unraveling the underlying mechanisms at the origin of ultra‐low thermal conductivity in pristine crystals is of central relevance to designing new functional materials. Here, a study of thermal conductivity κ(T) in an extended temperature range (1.5–400 K) is reported in the single‐crystall...
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Wiley
2025-08-01
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| Series: | Advanced Science |
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| Online Access: | https://doi.org/10.1002/advs.202502379 |
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| author | Alexandre Henriques Mariana S. L. Lima Gøran J. Nilsen Matthias J. Gutmann Steffen Wirth Walber H. Brito Valentina Martelli |
| author_facet | Alexandre Henriques Mariana S. L. Lima Gøran J. Nilsen Matthias J. Gutmann Steffen Wirth Walber H. Brito Valentina Martelli |
| author_sort | Alexandre Henriques |
| collection | DOAJ |
| description | Abstract Unraveling the underlying mechanisms at the origin of ultra‐low thermal conductivity in pristine crystals is of central relevance to designing new functional materials. Here, a study of thermal conductivity κ(T) in an extended temperature range (1.5–400 K) is reported in the single‐crystalline bismuthate perovskite BaBiO3. The measured κ(T) shows an anomalous glass‐like behavior with a ≈ T2 dependence at low temperatures and a plateau in a wide temperature range from about 20 to 260 K, surprisingly recovering the expected downturn for a crystal only for T > 300 K. The measured room temperature κ ≈ 1.6 W m−1 K−1 agrees with the calculated value, including three‐phonon and isotope disorder scattering. However, the departure of the experimental from the calculated κ(T) for T < 300 K, at the onset of the plateau, indicates that an additional scattering mechanism comes into play at lower temperatures. It is proposed that a tunneling two‐level system associated with the BiO6 octahedra rotation offers an additional phonon scattering mechanism and may explain the observed κ(T) suppression. The findings may have significant implications for the pairing mechanism and unconventional superconductivity of doped‐BaBiO3 aside from suggesting it as a candidate building block for functional heterostructures. |
| format | Article |
| id | doaj-art-c118f9fbaebc44058b0bd679f6e6ce75 |
| institution | Kabale University |
| issn | 2198-3844 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advanced Science |
| spelling | doaj-art-c118f9fbaebc44058b0bd679f6e6ce752025-08-23T14:14:17ZengWileyAdvanced Science2198-38442025-08-011231n/an/a10.1002/advs.202502379Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic InstabilityAlexandre Henriques0Mariana S. L. Lima1Gøran J. Nilsen2Matthias J. Gutmann3Steffen Wirth4Walber H. Brito5Valentina Martelli6Institute of Physics University of São Paulo São Paulo 05508‐090 BrazilInstitute of Physics University of São Paulo São Paulo 05508‐090 BrazilISIS Neutron and Muon Source Didcot Oxfordshire OX11 0QX UKISIS Neutron and Muon Source Didcot Oxfordshire OX11 0QX UKMax Planck Institute for Chemical Physics of Solids D‐01187 Dresden GermanyDepartment of Physics Federal University of Minas Gerais Belo Horizonte 31270‐901 BrazilInstitute of Physics University of São Paulo São Paulo 05508‐090 BrazilAbstract Unraveling the underlying mechanisms at the origin of ultra‐low thermal conductivity in pristine crystals is of central relevance to designing new functional materials. Here, a study of thermal conductivity κ(T) in an extended temperature range (1.5–400 K) is reported in the single‐crystalline bismuthate perovskite BaBiO3. The measured κ(T) shows an anomalous glass‐like behavior with a ≈ T2 dependence at low temperatures and a plateau in a wide temperature range from about 20 to 260 K, surprisingly recovering the expected downturn for a crystal only for T > 300 K. The measured room temperature κ ≈ 1.6 W m−1 K−1 agrees with the calculated value, including three‐phonon and isotope disorder scattering. However, the departure of the experimental from the calculated κ(T) for T < 300 K, at the onset of the plateau, indicates that an additional scattering mechanism comes into play at lower temperatures. It is proposed that a tunneling two‐level system associated with the BiO6 octahedra rotation offers an additional phonon scattering mechanism and may explain the observed κ(T) suppression. The findings may have significant implications for the pairing mechanism and unconventional superconductivity of doped‐BaBiO3 aside from suggesting it as a candidate building block for functional heterostructures.https://doi.org/10.1002/advs.202502379BaBiO3glass‐like thermal conductivityperovskitesunconventional superconductivity |
| spellingShingle | Alexandre Henriques Mariana S. L. Lima Gøran J. Nilsen Matthias J. Gutmann Steffen Wirth Walber H. Brito Valentina Martelli Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability Advanced Science BaBiO3 glass‐like thermal conductivity perovskites unconventional superconductivity |
| title | Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability |
| title_full | Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability |
| title_fullStr | Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability |
| title_full_unstemmed | Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability |
| title_short | Anomalous Glassy Thermal Conductivity in a Perovskite Bismuthate Induced by Structural Dynamic Instability |
| title_sort | anomalous glassy thermal conductivity in a perovskite bismuthate induced by structural dynamic instability |
| topic | BaBiO3 glass‐like thermal conductivity perovskites unconventional superconductivity |
| url | https://doi.org/10.1002/advs.202502379 |
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