Probing the ionic dielectric constant contribution in the ferroelectric phase of the Fabre salts

Página do item simplificado
dc.contributor.authorDe Souza, Mariano [UNESP]
dc.contributor.authorSquillante, Lucas [UNESP]
dc.contributor.authorSônego, Cesar [UNESP]
dc.contributor.authorMenegasso, Paulo [UNESP]
dc.contributor.authorFoury-Leylekian, Pascale
dc.contributor.authorPouget, Jean-Paul
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionUniversité Paris Saclay
dc.date.accessioned2018-12-11T17:17:21Z
dc.date.available2018-12-11T17:17:21Z
dc.date.issued2018-01-16
dc.description.abstractIn strongly correlated organic materials it has been pointed out that charge ordering could also achieve electronic ferroelectricity at the same critical temperature Tco. A prototype of such phenomenon are the quasi-one-dimensional (TMTTF)2X Fabre salts. However, the stabilization of a long-range ferroelectric ground state below Tco requires the break of inversion symmetry, which should be accompanied by a lattice deformation. In this paper we investigate the role of the monovalent counteranion X in such mechanism. For this purpose, we measured the quasistatic dielectric constant along the c∗-axis direction, where layers formed by donors and anions alternate. Our findings show that the ionic charge contribution is three orders of magnitude lower than the intrastack electronic response. The c∗ dielectric constant (ϵc∗′) probes directly the charge response of the monovalent anion X, since the anion mobility in the structure should help to stabilize the ferroelectric ground state. Furthermore, our ϵc∗′ measurements show that the dielectric response is thermally broaden below Tco if the ferroelectric transition occurs in the temperature range where the anion movement begin to freeze in their methyl groups cavity. In the extreme case of the PF6-H12 salt, where Tco occurs at the freezing point, a relaxor-type ferroelectricity is observed. Also, because of the slow kinetics of the anion sublattice, global hysteresis effects and reduction of the charge response upon successive cycling are observed. In this context, we propose that anions control the order-disorder or relaxation character of the ferroelectric transition of the Fabre salts. Yet, our results show that x-ray irradiation damages change the well-defined ferroelectric response of the AsF6 pristine salt into a relaxor.en
dc.description.affiliationSão Paulo State University (UNESP) IGCE Departamento de Física
dc.description.affiliationLaboratoire de Physique des Solides CNRS UMR 8502 Univers. Paris Sud Université Paris Saclay
dc.description.affiliationUnespSão Paulo State University (UNESP) IGCE Departamento de Física
dc.identifierhttp://dx.doi.org/10.1103/PhysRevB.97.045122
dc.identifier.citationPhysical Review B, v. 97, n. 4, 2018.
dc.identifier.doi10.1103/PhysRevB.97.045122
dc.identifier.file2-s2.0-85040588521.pdf
dc.identifier.issn2469-9969
dc.identifier.issn2469-9950
dc.identifier.scopus2-s2.0-85040588521
dc.identifier.urihttp://hdl.handle.net/11449/175749
dc.language.isoeng
dc.relation.ispartofPhysical Review B
dc.rights.accessRightsAcesso aberto
dc.sourceScopus
dc.titleProbing the ionic dielectric constant contribution in the ferroelectric phase of the Fabre saltsen
dc.typeArtigo

Arquivos

Pacote Original
Agora exibindo 1 - 1 de 1
Imagem de Miniatura
Nome:
2-s2.0-85040588521.pdf
Tamanho:
5.1 MB
Formato:
Adobe Portable Document Format
Descrição:
Baixar

Coleções

Artigos - Física - IGCE