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dc.contributor.authorPalomäki, Tommi
dc.contributor.authorWester, Niklas
dc.contributor.authorJohansson, Leena-Sisko
dc.contributor.authorLaitinen, Mikko
dc.contributor.authorJiang, Hua
dc.contributor.authorArstila, Kai
dc.contributor.authorSajavaara, Timo
dc.contributor.authorHan, Jeon G.
dc.contributor.authorKoskinen, Jari
dc.contributor.authorLaurila, Tomi
dc.date.accessioned2016-10-27T06:55:07Z
dc.date.available2018-10-15T21:35:29Z
dc.date.issued2016
dc.identifier.citationPalomäki, T., Wester, N., Johansson, L.-S., Laitinen, M., Jiang, H., Arstila, K., . . . Laurila, T. (2016). Characterization and Electrochemical Properties of Oxygenated Amorphous Carbon (a-C) Films. <em>Electrochimica Acta</em>, 220, 137-145. <a href="https://doi.org/10.1016/j.electacta.2016.10.063">doi:10.1016/j.electacta.2016.10.063</a>
dc.identifier.otherTUTKAID_71470
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/51694
dc.description.abstractAmorphous carbon (a-C) films with varying oxygen content were deposited by closed-field unbalanced magnetron sputtering with the aim to understand the effect of oxygen on the structural and physical properties of the films and subsequently correlate these changes with electrochemical properties. The a-C films were characterized by transmission electron microscopy, helium-ion microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and time-of-flight elastic recoil detection analysis. The electrochemical properties were studied by electrochemical impedance spectroscopy and cyclic voltammetry with several redox systems (Ru(NH3)62+/3+, Fe(CN)64−/3−, dopamine and ascorbic acid). The results indicated that the carbon films are amorphous with an ID/IG ratio near 2.6. The oxygen content of the films seemed to saturate at around 11 at. %, whereas the amount of surface oxygen functional groups increased steadily with increasing oxygen inflow during deposition. O/C ratio increased from 0.09 to 0.19. A significant increase in film resistivity was observed with increasing oxygen content. Lightly oxygenated a-C films showed a low charge transfer resistance (Rct) and reversible electron transfer for Ru(NH3)62+/3+ whereas both Rct and ΔEp increased considerably for heavily oxygenated films. The inner sphere redox systems were significantly affected by the surface oxygen functional groups with dopamine and ascorbic acid showing a linear increase in ΔEp and Epa, respectively, with increasing oxygen content. Fe(CN)64−/3− did not show a clear trend but was still clearly affected by the increase in oxygen content. The double layer capacitance was about 1 μF/cm2 for all the oxygenated a-C films.
dc.language.isoeng
dc.publisherPergamon Press; International Society of Electrochemistry
dc.relation.ispartofseriesElectrochimica Acta
dc.subject.otheroxygenated amorphous carbon
dc.subject.otherelectron transfer
dc.subject.othercyclic voltammetry
dc.subject.otherelectrochemical impedance spectroscopy
dc.subject.otherunbalanced magnetron sputtering
dc.titleCharacterization and Electrochemical Properties of Oxygenated Amorphous Carbon (a-C) Films
dc.typearticle
dc.identifier.urnURN:NBN:fi:jyu-201610214412
dc.contributor.laitosFysiikan laitosfi
dc.contributor.laitosDepartment of Physicsen
dc.type.urihttp://purl.org/eprint/type/JournalArticle
dc.date.updated2016-10-21T12:15:18Z
dc.type.coarjournal article
dc.description.reviewstatuspeerReviewed
dc.format.pagerange137-145
dc.relation.issn0013-4686
dc.relation.volume220
dc.type.versionacceptedVersion
dc.rights.copyright© 2016 Elsevier Ltd. This is a final draft version of an article whose final and definitive form has been published by Elsevier. Published in this repository with the kind permission of the publisher.
dc.rights.accesslevelopenAccessfi
dc.relation.doi10.1016/j.electacta.2016.10.063


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