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Title: Glass-like thermal conductivity in nanostructures of a complex anisotropic crystal

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Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 96; Journal Issue: 21; Related Information: CHORUS Timestamp: 2017-12-13 10:31:53; Journal ID: ISSN 2469-9950
American Physical Society
Country of Publication:
United States

Citation Formats

Weathers, Annie, Carrete, Jesús, DeGrave, John P., Higgins, Jeremy M., Moore, Arden L., Kim, Jaehyun, Mingo, Natalio, Jin, Song, and Shi, Li. Glass-like thermal conductivity in nanostructures of a complex anisotropic crystal. United States: N. p., 2017. Web. doi:10.1103/PhysRevB.96.214202.
Weathers, Annie, Carrete, Jesús, DeGrave, John P., Higgins, Jeremy M., Moore, Arden L., Kim, Jaehyun, Mingo, Natalio, Jin, Song, & Shi, Li. Glass-like thermal conductivity in nanostructures of a complex anisotropic crystal. United States. doi:10.1103/PhysRevB.96.214202.
Weathers, Annie, Carrete, Jesús, DeGrave, John P., Higgins, Jeremy M., Moore, Arden L., Kim, Jaehyun, Mingo, Natalio, Jin, Song, and Shi, Li. 2017. "Glass-like thermal conductivity in nanostructures of a complex anisotropic crystal". United States. doi:10.1103/PhysRevB.96.214202.
title = {Glass-like thermal conductivity in nanostructures of a complex anisotropic crystal},
author = {Weathers, Annie and Carrete, Jesús and DeGrave, John P. and Higgins, Jeremy M. and Moore, Arden L. and Kim, Jaehyun and Mingo, Natalio and Jin, Song and Shi, Li},
abstractNote = {},
doi = {10.1103/PhysRevB.96.214202},
journal = {Physical Review B},
number = 21,
volume = 96,
place = {United States},
year = 2017,
month =

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on December 13, 2018
Publisher's Accepted Manuscript

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  • Here, ultrafast time-domain thermoreflectance (TDTR) is utilized to extract the through-plane thermal conductivity (Λ LSCO) of epitaxial La 0.5Sr 0.5CoO 3–δ (LSCO) of varying thickness (<20 nm) on LaAlO 3 and SrTiO 3 substrates. These LSCO films possess ordered oxygen vacancies as the primary means of lattice mismatch accommodation with the substrate, which induces compressive/tensile strain and thus controls the orientation of the oxygen vacancy ordering (OVO). TDTR results demonstrate that the room-temperature Λ LSCO of LSCO on both substrates (1.7 W m –1 K –1) are nearly a factor of four lower than that of bulk single-crystal LSCO (6.2more » W m –1 K –1). Remarkably, this approaches the lower limit of amorphous oxides (e.g., 1.3 W m –1 K –1 for glass), with no dependence on the OVO orientation. Through theoretical simulations, origins of the glass-like thermal conductivity of LSCO are revealed as a combined effect resulting from oxygen vacancies (the dominant factor), Sr substitution, size effects, and the weak electron/phonon coupling within the LSCO film. The absence of OVO dependence in the measured Λ LSCO is rationalized by two main effects: (1) the nearly isotropic phononic thermal conductivity resulting from the imperfect OVO planes when δ is small; (2) the missing electronic contribution to Λ LSCO along the through-plane direction for these ultrathin LSCO films on insulating substrates.« less
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