Impedance spectroscopy study of nickel electrodeposits

Karayianni, HS; Patermarakis, GS; Papaioannou, JC

dc.contributor.author	Karayianni, HS	en
dc.contributor.author	Patermarakis, GS	en
dc.contributor.author	Papaioannou, JC	en
dc.date.accessioned	2014-03-01T01:17:58Z
dc.date.available	2014-03-01T01:17:58Z
dc.date.issued	2002	en
dc.identifier.issn	0167-577X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14733
dc.subject	Hydrogen hopping/diffusion conduction mechanism	en
dc.subject	Impedance spectroscopy	en
dc.subject	Microstructure model	en
dc.subject	Nickel electrodeposits	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.classification	Physics, Applied	en
dc.subject.other	Diffusion	en
dc.subject.other	Electrodeposition	en
dc.subject.other	Electrolytes	en
dc.subject.other	Electron microscopy	en
dc.subject.other	Microstructure	en
dc.subject.other	X ray diffraction analysis	en
dc.subject.other	Impedance spectroscopy	en
dc.subject.other	Nickel	en
dc.title	Impedance spectroscopy study of nickel electrodeposits	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0167-577X(01)00459-1	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0167-577X(01)00459-1	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	Nickel electrodeposits prepared in NiSO4 and NiCl2 electrolytes with thicknesses of 43-49.4 mum were examined by the impedance spectroscopy (IS) method for a-c frequencies 1 Hz-100 kHz. The Nyquist diagrams were single, almost perfect semicircles, suggesting the applicability of the in parallel combination of the R-a-C-a elements characterised by a single relaxation time, 8.27 x 10(-6) s, combined in series with another R-b element, R-b much less than R-a. This relaxation time predicted that the incorporated hydrogen atoms are involved in the process of conduction by a hopping/diffusion mechanism, which is differentiated in the cases of NiSO4-Ni and NiCl2-Ni deposits. The diffusion coefficient of hydrogen, 1.25 x 10(-11)cm(2) s(-1), was determined. The microstructure of Ni electrodeposits was also studied and characterised by electron microscopy. Finally, a general model for the microstructure of Ni electrodeposits, consistent with the results of impedance spectroscopy, was formulated. (C) 2002 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Materials Letters	en
dc.identifier.doi	10.1016/S0167-577X(01)00459-1	en
dc.identifier.isi	ISI:000174159900016	en
dc.identifier.volume	53	en
dc.identifier.issue	1-2	en
dc.identifier.spage	91	en
dc.identifier.epage	101	en