Anees Pazhedath^1*, Lorenzo Bastonero^1*, Nicola Marzari^1,2,3*, Michele Simoncelli^4*

1 U Bremen Excellence Chair, Bremen Center for Computational Materials Science, and MAPEX Center for Materials and Processes, University of Bremen, D-28359 Bremen, Germany

2 Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, Switzerland

3 Laboratory for Materials Simulations, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland

4 Cavendish Laboratory, Theory of Condensed Matter Group, University of Cambridge, United Kingdom

* Corresponding authors emails: anees@uni-bremen.de, lbastone@uni-bremen.de, nicola.marzari@epfl.ch, ms2855@cam.ac.uk

DOI10.24435/materialscloud:ft-j0 [version v1]

Publication date: Sep 27, 2023

How to cite this record

Anees Pazhedath, Lorenzo Bastonero, Nicola Marzari, Michele Simoncelli, First-principles characterization of thermal conductivity in LaPO₄-based alloys, Materials Cloud Archive 2023.149 (2023), doi: 10.24435/materialscloud:ft-j0.

Description

Alloys based on lanthanum phosphate (LaPO₄) are often employed as thermal barrier coatings, due to their low thermal conductivity and structural stability over a wide temperature range. To enhance the thermal-insulation performance of these alloys, it is essential to comprehensively understand the fundamental physics governing their heat conduction. Here, we employ the Wigner formulation of thermal transport in conjunction with first-principles calculations to elucidate how the interplay between anharmonicity and compositional disorder determines the thermal properties of La_1-xGd_xPO₄ alloys, and discuss the fundamental physics underlying the emergence and coexistence of particle-like and wave-like heat-transport mechanisms. Our predictions for microscopic vibrational properties (temperature-dependent Raman spectrum) and for macroscopic thermal conductivity are validated against experiments. Finally, we leverage these findings to devise strategies to optimize the performance of thermal barrier coatings.

Materials Cloud sections using this data

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File name	Size	Description
data-LaPO4.zip MD5md5:61e1096b1e0dcce6e2987b498d88c641	4.1 MiB	Thermal transport in LaPO4-based alloys studied in the paper "First-principles characterization of thermal conductivity in LaPO4-based alloys" by A. Pazhedath, L. Bastonero, N. Marzari, and M. Simoncelli

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Keywords

Thermal transport Alloys Thermal barrier coating First-principles Anharmonicity and disorder