Oxidation barrier of Cu and Fe powder by Atomic Layer Deposition

SURFACE & COATINGS TECHNOLOGY

卷:349

Article

Cremers, Veronique¹  Rampelberg, Geert¹  Barhoum, Ahmed²  Walters, Perry²  Claes, Nathalie⁴  de Oliveira, Thais Milagres⁴  Van Assche, Guy³  Bals, Sara⁴  Dendooven, Jolien¹  Detavernier, Christophe¹ 

[1] Univ Ghent, Dept Solid State Sci, Krijgslaan 281-S1, B-9000 Ghent, Belgium

[2] Helwan Univ, Chem Dept, Fac Sci, Cairo 11795, Egypt

[3] VUB, Phys Chem & Polymer Sci, Pl Laan 2, B-1050 Brussels, Belgium

[4] Univ Antwerp, Electron Microscopy Mat Res EMAT, Groenenborgerlaan 171, B-2020 Antwerp, Belgium

关键词: Atomic Layer Deposition;    ALD;    Powder;    Oxdidation barrier;   

DOI  :  10.1016/j.surfcoat.2018.06.048

来源: Elsevier

【 摘 要 】

Atomic Layer Deposition (ALD) is a vapor based technique which allows to deposit uniform, conformal films with a thickness control at the atomic scale. In this research, Al2O3 coatings were deposited on micrometer-sized Fe and Cu powder (particles) using the thermal trimethylaluminum (TMA)/water (H2O) process in a rotary pump-type ALD reactor. Rotation of the powder during deposition was required to obtain a pinhole-free AID coating. The protective nature of the coating was evaluated by quantifying its effectiveness in protecting the metal particles during oxidative annealing treatments. The Al2O3 coated powders were annealed in ambient air while in-situ thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) data were acquired. The thermal stability of a series of Cu and Fe powder with different Al2O3 thicknesses were determined with TGA. In both samples a dear shift in oxidation temperature is visible. For Cu and Fe powder coated with 25 nor Al2O3, we observed an increase of the oxidation temperature with 300-400 degrees C. For the Cu powder a thin film of only 8 nm is required to obtain an initial increase in oxidation temperature of 200 degrees C. In contrast, for Fe powder a thicker coating of 25 nm is required. In both cases, the oxidation temperature increases with increasing thickness of the Al2O3 coating. These results illustrate that the Al2O3 thin film, deposited by the thermal ALD process (TMA/H2O) can be an efficient and pinhole-free barrier layer for micrometer-sized powder particles, provided that the powder is properly agitated during the process to ensure sufficient vapor-solid interaction.

【 授权许可】

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