Thermal conductivity reduction in (Zr0.25Ta0.25Nb0.25Ti0.25)C high entropy carbide from extrinsic lattice defects

High entropy carbides ceramics with randomly-distributed multiple principal cations have shown high temperature stability, low thermal conductivity, and possible radiation tolerance. While chemical disorder has been shown to suppress thermal conductivity in these materials, little investigation has...

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Bibliographic Details
Main Authors: Cody A. Dennett, Zilong Hua, Eric Lang, Fei Wang, Bai Cui
Format: Article
Language:English
Published: Taylor & Francis Group 2022-09-01
Series:Materials Research Letters
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/21663831.2022.2078678
Description
Summary:High entropy carbides ceramics with randomly-distributed multiple principal cations have shown high temperature stability, low thermal conductivity, and possible radiation tolerance. While chemical disorder has been shown to suppress thermal conductivity in these materials, little investigation has been made on the effects of additional, extrinsically-generated structural defects on thermal transport. Here, (Zr[Formula: see text]Ta[Formula: see text]Nb[Formula: see text]Ti[Formula: see text])C is exposed to Zr ions to generate a micron-scale, structural-defect-bearing layer. The reduction in lattice thermal transport is measured using laser thermoreflectance. Conductivity changes from different implantation temperatures suggest dislocation loops contribute little to phonon scattering while nanoscale defects serve as effective scatterers, offering a pathway for thermal engineering.
ISSN:2166-3831