abstract
Morphology modification of ferroelectric materials at the nanoscale is an important aspect for further development of ferroelectrics. In this work, the synthesis of nanoporous barium titanate prepared under the assistance of Pluronic PE 10300 block copolymer is reported. Nanopores reside inside the BaTiO3 crystallites that exhibit a specific BET surface area around 70 m(2)/g and nanopore volume fraction of 44.7%. X-ray diffraction of nanoporous BaTiO3 indicates an average cubic structure while Raman spectra suggest local structural distortions of the lattice. With Landauer-Bruggeman effective medium approximation (LB-EMA), the dielectric constant (at 1 MHz) of nanoporous BaTiO3 and solid BaTiO3 (excluding all porosity) was estimated as 112 and 706, respectively, implying,in effective way to manipulate the dielectric constant of materials by introducing nanopores.
keywords
SOFT-MODE SPECTROSCOPY; X-RAY-DIFFRACTION; BARIUM-TITANATE; THIN-FILMS; PARTICLES; FERROELECTRICITY; CONSTANTS; CERAMICS; OXIDES; MERIT
subject category
Chemistry; Materials Science
authors
Hou, RZ; Ferreira, P; Vilarinho, PM
our authors
Paula Celeste da Silva Ferreira
Coordinating Researcher
Paula Maria Lousada Silveirinha Vilarinho
Vice Directoracknowledgements
The authors are thankful to Dr. Marc Willinger for HRTEM characterizations. Dr. Mariana Sardo and Prof. Paulo Claro are acknowledged for the help with Raman spectroscopy. The authors are grateful to BASF for providing the block copolymer. This work was funded by FCT under Grant SFRH/BPD/26711/2006, FEDER and European Network of Excellence FAME under Contract FP6-500159-1