Cation-oxygen interaction and oxygen stability in CaCu3Ti4O12 and CdCu3Ti4O12 lattices

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dc.contributor.authorMatos, M.
dc.contributor.authorWalmsley, L.
dc.contributor.institutionPontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-20T15:23:08Z
dc.date.available2014-05-20T15:23:08Z
dc.date.issued2006-02-08
dc.description.abstractThe cubic perovskite related material CaCu3Ti4O12 has attracted a great deal of attention due to the high values of the static dielectric constant, of order 104, approximately constant in the temperature range 100-600 K. The substitution of Ca by Cd results in a similar temperature dependence but a static dielectric constant more than one order of magnitude lower. A theoretical electronic structure study is performed on CaCu3Ti4O12 (CCTO) and CdCu3Ti4O12 (CdCTO) using a tight binding with overlap method. Although the calculations are performed in a paramagnetic configuration, excellent agreement with experiment was found for the calculated band gap of CCTO. In spite of the fact that the band structures of both systems look practically the same, a significant difference is found in the calculated bond strength of Ca-O and Cd-O pairs, driven by the presence of Ti, with Ca-O interaction in CCTO loosened with respect to Cd-O interaction in the cadmium compound. It is suggested that O vacancies are more easily formed in CCTO, this being related to the lower electronegativity of Ca as compared to Cd. The formation of oxygen vacancies could be the origin of the difference in the static dielectric constant of the two compounds.en
dc.description.affiliationPUC Rio, Dept Fis, BR-38071 Rio de Janeiro, Brazil
dc.description.affiliationUniv Estadual Paulista, Inst Geociencias & Ciências Exatas, Dept Fis, BR-13500970 Rio Claro, SP, Brazil
dc.description.affiliationUnespUniv Estadual Paulista, Inst Geociencias & Ciências Exatas, Dept Fis, BR-13500970 Rio Claro, SP, Brazil
dc.format.extent1793-1803
dc.identifierhttp://dx.doi.org/10.1088/0953-8984/18/5/030
dc.identifier.citationJournal of Physics-condensed Matter. Bristol: Iop Publishing Ltd, v. 18, n. 5, p. 1793-1803, 2006.
dc.identifier.doi10.1088/0953-8984/18/5/030
dc.identifier.issn0953-8984
dc.identifier.urihttp://hdl.handle.net/11449/33982
dc.identifier.wosWOS:000235921400033
dc.language.isoeng
dc.publisherIop Publishing Ltd
dc.relation.ispartofJournal of Physics: Condensed Matter
dc.relation.ispartofjcr2.617
dc.relation.ispartofsjr0,875
dc.rights.accessRightsAcesso restrito
dc.sourceWeb of Science
dc.titleCation-oxygen interaction and oxygen stability in CaCu3Ti4O12 and CdCu3Ti4O12 latticesen
dc.typeArtigo
dcterms.licensehttp://iopscience.iop.org/page/copyright
dcterms.rightsHolderIop Publishing Ltd
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Geociências e Ciências Exatas, Rio Claropt

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