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Title: The importance of anharmonicity in thermal transport across solid-solid interfaces

Understanding interfacial thermal transport is of great importance for applications like energy devices and thermal management of electronics. Despite the significant efforts in the past few decades, thermal transport across solid-solid interfaces is still not fully understood and cannot be accurately predicted. Anharmonicity is often ignored in many prediction models, such as the mismatch models, the wave-packet method, and the Atomic Green's function. In this paper, we use molecular dynamics to systematically study the role of anharmonicity in thermal transport across solid-solid interfaces. The interatomic interactions are modeled using force constants up to the third order. This model allows controlling the anharmonicity independently by tuning the cubic force constants. The interfacial thermal conductance as a function of anharmonicity inside the materials and that at the interface is studied. We found that the anharmonicity inside the materials plays an important role in the interfacial thermal transport by facilitating the energy communication between different phonon modes. The anharmonicity at the interface has much less impact on the interfacial thermal transport. These results are important to the modification of traditional models to improve their prediction power.
Authors:
 [1] ;  [1] ;  [2]
  1. Aerospace and Mechanical Engineering, University of Notre Dame, 371 Fitzpatrick Hall-Notre Dame, Indiana 46556 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22271300
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; GREEN FUNCTION; HETEROJUNCTIONS; INTERFACES; MOLECULAR DYNAMICS METHOD; PHONONS; SOLIDS; THERMAL CONDUCTION; THERMAL CONDUCTIVITY; WAVE PACKETS