Systematic investigation of the misorientation- and temperature-dependent Kapitza resistance in CeO2. (August 2016)

• Record Type: Journal Article
• Authors: Chernatynskiy, Aleksandr; Bai, Xian-Ming; Gan, Jian
• Is Part Of: International journal of heat and mass transfer. Volume 99(2016:Aug.)
• Page Start: 461
• Page End: 469
• Publication Date: 2016-08
• Subjects: Thermal conductivity -- Kapitza resistance -- Grain boundary -- Cerium dioxide -- Molecular dynamics -- Misorientation angle dependence; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2016.03.105
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Read–Shockley-like model is developed for grain-boundary-misorientation-dependent Kapitza resistance in ceria. Sufficient statistics shows that Kapitza resistance correlates with the grain boundary energy strongly. Best classical potential for thermal transport in ceria is identified. 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.