Memorias de investigación
Research Publications in journals:
Proofs of the Coexistence of Two Magnetic Contributions in Pure and Doped CaCu3Ti4O12 Giant Dielectric Constant Ceramics
Year:2009

Research Areas
  • Materials,
  • Ceramics,
  • Magnetic materials

Information
Abstract
Abstract: Fe3+ - or Nb5+-doped CaCu3Ti4O12 (CCTO) ceramics show higher values of both room-temperature (RT) grain conductivity and dielectric constant than undoped ceramics. Microstructural and structural characterization combined with magnetic properties reveal the coexistence of two components that seem relevant for the dielectric behavior of the material. The grain possesses a nanostructure characterized by layered domains with thicknesses <80 nm. The formation of the layered domains is associated with the evidence of different chemical states as Cu2+/Cu+ and Ti4+/Ti3+ that are present in the material. The magnetic contribution is related to two coupled effects: the antiferromagnetic (AFM) response with T-N = 25 K ascribed to Cu2+, and a paramagnetic-like contribution attributed to Ti3+ cations. The coexistence of two coupled magnetic contributions could explain the proposed unusual coupling of the AFM Cu2+ superexchange interaction through the nonmagnetic Ti4+ rather than via the usual oxygen coupling. The lower the paramagnetic-like contribution at RT, the larger the conductivity and the dielectric constant of the material are. Below 150 K, the increase of the paramagnetic-like contribution is correlated with the low transition temperature of the CCTO.
International
Si
JCR
Si
Title
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
ISBN
0002-7820
Impact factor JCR
2,101
Impact info
Volume
92
10.1111/j.1551-2916.2009.03224.x
Journal number
10
From page
2311
To page
2318
Month
OCTUBRE
Ranking
Participants
  • AUTOR: ADRIAN QUESADA ICV-CSIC
  • AUTOR: JOSE LUIS GARCIA FIERRO IMM-CSIC
  • AUTOR: MIGUEL ANGEL GARCIA ICV-CSIC
  • AUTOR: JUAN JOSE ROMERO ICV-CSIC
  • Autor: Miguel Ángel De La Rubia López UPM
  • Autor: Jose Francisco Fernández Lozano UPM
  • AUTOR: JOSE LUIS COSTA KRAMER IMM-CSIC
  • AUTOR: PILAR LERET ICV-CSIC
  • Autor: Jose de Frutos Vaquerizo UPM
  • AUTOR: SOLEDAD MARTIN GONZALEZ ICA-CSIC

Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Propiedades ópticas, eléctricas y magnéticas de materiales y sus aplicaciones (POEMMA)
  • Departamento: Física Aplicada a las Tecnologías de la Información