Study of anodic oxide films formed on solid-state sintered SiC-ceramic at high anodic potentials
Publikation: Beitrag in Fachzeitschrift › Forschungsartikel › Beigetragen › Begutachtung
Beitragende
Abstract
The present work studies the formation, chemical composition, and structure of an oxide layer formed on the technical solid-state sintered ceramic (EKasic®D) in a strong alkaline solution (1 M NaOH at pH 14) at high anodic potentials (30 V vs. 3 M Ag/AgCl). The observed formation of oxide films on SiC in alkaline solution is in contradiction to the thermodynamic laws (Pourbaix-diagram). The film thickness was determined by SEM/EDX measurements using the specific thin film analysis tool “AZtec” (Oxford Instruments) as well as the transmission electron microscopy. The thickness of the oxide film formed at 30 V amounts to 30 nm that corresponds with a field strength of E = 10 MV cm−1, which corresponds with the formation according to the high-field mechanism. The chemical composition was studied by EDX-analysis in a transmission electron microscope as well as by X-ray photoelectron spectroscopy (XPS). The oxide layer is completely amorphous and consists of non-stoichiometric SiOx and SiOxCy. The layer is assumed as graded with a higher amount of SiOx in the outermost regions and an increased amount of SiOxCy in the inner region of the passive layer. Additionally, the passive layer is doped by a small amount of aluminum originating from a sinter additive used in the manufacture of the SiC ceramic and completely incorporated into the SiC grains.
Details
Originalsprache | Englisch |
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Seiten (von - bis) | 15010-15016 |
Seitenumfang | 7 |
Fachzeitschrift | Ceramics international |
Jahrgang | 47 |
Ausgabenummer | 11 |
Publikationsstatus | Veröffentlicht - 1 Juni 2021 |
Peer-Review-Status | Ja |
Extern publiziert | Ja |
Schlagworte
ASJC Scopus Sachgebiete
Schlagwörter
- Anodic oxide formation, SiC-Ceramics, XPS-Studies