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dc.contributor.authorMitsari, Efstratia
dc.contributor.authorRomanini, Michela
dc.contributor.authorBarrio Casado, María del
dc.contributor.authorTamarit Mur, José Luis
dc.contributor.authorMacovez, Roberto
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Física
dc.date.accessioned2017-05-12T09:46:05Z
dc.date.issued2017-03-09
dc.identifier.citationMitsari, E., Romanini, M., Del Barrio, M., Tamarit, J. Ll., Macovez, R. Protonic surface conductivity and proton space-charge relaxation in hydrated fullerol. "The journal of physical chemistry. Part C, nanomaterials and interfaces", 9 Març 2017, vol. 121, núm. 9, p. 4873-4881.
dc.identifier.issn1932-7447
dc.identifier.urihttp://hdl.handle.net/2117/104351
dc.description.abstractThe ac dielectric properties of both anhydrous fullerol (C-60(OH)(24)) and hydrated fullerol with 20% water mass content are investigated by means of temperature-dependent dielectric spectroscopy. Anhydrous polycrystalline fullerol exhibits charge transport mediated by hopping of electronic charge carriers. Hydrated fullerol has a dc conductivity higher by more than a factor of 10(3) than that of the anhydrous sample due to water-induced proton transport. Four distinct dielectric relaxation processes are observed in hydrated fullerol, two of which lie in the frequency range of the electrode polarization. The fastest relaxation is only observed below the melting point of pure water and is assigned to the migration of hydrogen-bond defects in the physisorbed H2O layers. The other three processes exhibit nonmonotonous temperature dependence upon dehydration by heating. The fastest of the three is present also in the anhydrous powder, and it is assigned to a space-charge relaxation due to accumulation of electronic charge carriers at samples heterogeneities such as grain boundaries. By studying the temperature dependence of the two slower relaxations across dehydration, we identify them as separate electrode polarization effects due to distinct charge carriers, namely electrons and protons. The electronic electrode polarization is also present in pure fullerol, while the proton space-charge relaxation is only present in the hydrated material. Our findings help elucidate the hitherto puzzling observation of more than one nonmonotonous relaxation process in hydrated and water-containing systems.
dc.format.extent9 p.
dc.language.isoeng
dc.subjectÀrees temàtiques de la UPC::Física
dc.subjectÀrees temàtiques de la UPC::Enginyeria dels materials
dc.subject.lcshDielectric relaxation
dc.subject.lcshHydration
dc.titleProtonic surface conductivity and proton space-charge relaxation in hydrated fullerol
dc.typeArticle
dc.subject.lemacRelaxació dielèctrica
dc.subject.lemacHidratació
dc.contributor.groupUniversitat Politècnica de Catalunya. GCM - Grup de Caracterització de Materials
dc.identifier.doi10.1021/acs.jpcc.6b12530
dc.relation.publisherversionhttp://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b12530
dc.rights.accessRestricted access - publisher's policy
local.identifier.drac20096226
dc.description.versionPostprint (author's final draft)
dc.date.lift10000-01-01
local.citation.authorMitsari, E.; Romanini, M.; Del Barrio, M.; Tamarit, J. Ll.; Macovez, R.
local.citation.publicationNameThe journal of physical chemistry. Part C, nanomaterials and interfaces
local.citation.volume121
local.citation.number9
local.citation.startingPage4873
local.citation.endingPage4881


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