Interfacial mechanisms of surface-modified diamond particles in enhancing thermal conductivity of diamond/indium composites
Journal
Diamond and Related Materials
Journal Volume
167
Start Page
113826
ISSN
09259635
Date Issued
2026-08
Author(s)
Abstract
Diamond/indium composites are promising soft-metal thermal interface materials (TIMs), but their thermal performance is limited by the high effective interfacial thermal resistance between diamond particles and the indium matrix. In this work, diamond/indium composites were fabricated by thermo-compression sintering, with the diamond particles modified using 50% H2SO4 etching and He/H2 plasma treatments. Atomic force microscopy (AFM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses showed that H2SO4 etching produced a strongly roughened diamond surface with a reduced sp2 carbon fraction, whereas He/H2 plasma treatment induced partial surface graphitization and increased the sp2 fraction. At 50 vol% diamond, the thermal diffusivity α increased from 49 mm2 s−1 for the as-prepared composite to 75 and 77 mm2 s−1 for the H2SO4-etched and He/H2 plasma-treated composites, respectively, corresponding to enhancements of 56% and 60%. Differential effective medium (DEM) analysis further estimated that the effective diamond/indium interfacial thermal resistance decreased from 3.4 × 10−7 to 2.59 × 10−7 and 1.29 × 10−7 (m2 K W−1) after H2SO4 etching and He/H2 plasma treatment, respectively. In addition to the experimental results, simplified two-dimensional thermal simulations were conducted as a sensitivity analysis. Under a fixed DEM-derived interfacial thermal resistance, roughened diamond surfaces showed a higher effective thermal conductivity than smooth surfaces, indicating the contribution of interfacial morphology. When the diamond surface was kept smooth, reducing the DEM-derived interfacial thermal resistance also increased the simulated effective thermal conductivity. Overall, both surface modification methods effectively improve the thermal transport of diamond/indium composites and reduce the interfacial thermal resistance, highlighting their potential for TIM applications.
Subjects
Diamond particles
Indium
Surface modification
Thermal interface materials
Publisher
Elsevier Ltd
Type
journal article