Probing the validity of the diffuse mismatch model for phonons using atomistic simulations

Rohit R. Kakodkar and Joseph P. Feser
Phys. Rev. B 95, 125434 – Published 27 March 2017

Abstract

Due to its simplicity the diffuse mismatch model (DMM) remains a popular description of phonon transmission across solid-solid boundaries. However, it remains unclear in which situations the DMM should be expected to be a valid model of the underlying physics. Here its validity is investigated mode-by-mode using a three-dimensional extension of the frequency domain, perfectly matched layer (FD-PML) method, to study the interface between face-centered cubic solids with interdiffused atoms. While submonolayer levels of interdiffusion are found to increase the number of available modes for transmission, consistent qualitatively with the DMM, we do not find quantitative or qualitative convergence toward the DMM at higher levels of interdiffusion. In particular, contrary to the fundamental assumption of the DMM, modes are not found to lose memory of their initial polarization and wave vector. The transmission coefficients of randomly interdiffused and smoothly graded interfaces are also compared. While smoothly graded interfaces show strong antireflection properties, selection rules still prohibit transmission of many modes, whereas interdiffused interfaces are not subject to such rules and achieve similar thermal interface conductance by transmitting with lower probability but using a wider range of modes.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 8 July 2016
  • Revised 13 January 2017

DOI:https://doi.org/10.1103/PhysRevB.95.125434

©2017 American Physical Society

Physics Subject Headings (PhySH)

  1. Research Areas
  1. Physical Systems
Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Rohit R. Kakodkar and Joseph P. Feser*

  • Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716, USA

  • *jpfeser@udel.edu

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 95, Iss. 12 — 15 March 2017

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×