skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on June 30, 2018

Title: Lattice thermal transport in L a 3 C u 3 X 4 compounds ( X = P , As , Sb , Bi ) : Interplay of anharmonicity and scattering phase space

Thermal conductivities of La 3Cu 3X 4(X=P,As,Sb,Bi) compounds are examined using first-principles density functional theory and Boltzmann transport methods. We observe a trend of increasing lattice thermal conductivity (κl) with increasing atomic mass, challenging our expectations, as lighter mass systems typically have larger sound speeds and weaker intrinsic scattering. In particular, we find that La 3Cu 3P 4 has the lowest κ l, despite having larger sound speed and the most restricted available phase space for phonon-phonon scattering, an important criterion for estimating and comparing κ l among like systems. The origin of this unusual behavior lies in the strength of the individual anharmonic phonon scattering matrix elements, which are much larger in La 3Cu 3P 4 than in the heavier La 3Cu 3Bi 4 system. Lastly, our finding provides insights into the interplay of harmonic and anharmonic properties of complex, low-thermal-conductivity compounds, of potential use for thermoelectric and thermal barrier coating applications.
Authors:
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 22; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1376474
Alternate Identifier(s):
OSTI ID: 1372521