Impact of irradiation induced dislocation loops on thermal conductivity in ceramics

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Institutes & Expert groups

  • UW - University of Wisconsin-Madison
  • INL - Idaho national Laboratory
  • OSU -The Ohio State University

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Abstract

Experimental work aimed at understanding the role of dislocation loops in limiting phonon mediated thermal transport in ceramics is presented. Faulted dislocation loops, having diameters of a few nanometers, were introduced by irradiating a polycrystalline cerium dioxide sample with 1.6 MeV protons at 700°C. XRD analysis indicated that irradiated samples retained their crystalline structure and exhibit very little lattice expansion suggesting a low concentration of point defects. Further microstructure characterization using transmission electron microscopy revealed that interstitial type faulted dislocation loops were primarily created as expected for these irradiation conditions. Thermal conductivity of the damaged layer was measured using a modulated thermoreflectance approach. Analysis of the experimental data using the classical Klemens‐Callaway approach reveals that the conductivity reduction is primarily due to dislocation loops, while point defects and voids play only a minor role. These results provide experimental confirmation that faulted loops offer a unique arrangement for displaced atoms that leads to an unusually large reduction of thermal conductivity.

Details

Original languageEnglish
Pages (from-to)7533-7542
Number of pages10
JournalJournal of the american ceramic society
DOIs
Publication statusPublished - 30 May 2019

Keywords

  • dislocation loops, radiation damage, thermal conductivity

ID: 5640901