Systematic Investigation of the Misorientation- and Temperature-Dependent Kapitza Resistance in CeO₂

Abstract

The misorientation- and temperature-dependent grain boundary thermal (Kapitza) resistance in CeO2 is investigated using molecular dynamics simulations. A few empirical potentials for molecular dynamics simulations are evaluated for their predicted properties such as the phonon dispersion curves, bulk thermal conductivity, and grain boundary structures. Through the comparison of these properties with experimental results, the most reasonable potential (Gotte2007) is selected. The Kapitza resistances of tilt and twist grain boundaries with misorientation angles ranging from 3°to 87°are calculated and a clear transition angle at about 16°is observed. The Kapitza resistance is found to increase almost linearly with misorientation angle in the low-angle regime but remain nearly constant at the high-angle regime, a behavior very similar to the grain boundary energy. A nearly linear correlation between Kapitza resistance and grain boundary energy is thus obtained. Similar to the grain boundary energy, the Read-Shockley model can well describe the misorientation-dependent Kapitza resistance at low-angle regime. The Kapitza conductance (the inverse of Kapitza resistance) is found to increase almost linearly with temperature in our simulations.

Department(s)

Physics

Research Center/Lab(s)

Center for High Performance Computing Research

Keywords and Phrases

Grain Boundaries; Molecular Dynamics; Bulk Thermal Conductivity; Cerium Dioxides; Grain Boundary Structure; Grain-Boundary Energy; Kapitza Resistance; Misorientation Angle; Molecular Dynamics Simulations; Phonon Dispersion Curves; Thermal Conductivity

International Standard Serial Number (ISSN)

0017-9310

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 Elsevier Ltd, All rights reserved.

Publication Date

01 Aug 2016

Link to Full Text

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