Controlled growth of silica shell on Ba0.6Sr0.4TiO3 nanoparticles used as precursors of ferroelectric composites

Stéphane Mornet (1) , Catherine Elissalde (1) , Virginie Hornebecq (2) , Olivier Bidault (1) , Etienne Duguet (1) , Alain Brisson (3) , Mario Maglione (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 MADIREL - Matériaux divisés, interfaces, réactivité, électrochimie
3 IECB - Imagerie Moléculaire et Nanobiotechnologies - Institut Européen de Chimie et Biologie

A method based on a seeded growth process was developed to coat ferroelectric nanoparticles with a dielectric silica shell. This method, applied to size-polydispersed (Ba0.6Sr0.4)TiO3 particles (BST, mean diameter 150 nm), allows the control of the silica shell thickness from 2 to 80 nm with an accuracy of 1-2 nm. The morphology and surface physical chemistry of the core-shell were studied by transmission electron microscopy, photon correlation spectroscopy, and zeta potential measurements. A size-sorting procedure consisting of several cycles of centrifugation was optimized to extract the BST@silica nanoparticles of the required size for dielectric properties tuning. Upon sintering, dielectric measurements showed that the ferroelectric transition was maintained in the dense nanocomposites.

Mots clés: Nanoparticles; Silica; Ferroelectrics; Composites; Core-shell; Growth; Ba0.6Sr0.4TiO3

Domaines: Matériaux

Stéphane Mornet, Catherine Elissalde, Virginie Hornebecq, Olivier Bidault, Etienne Duguet, et al.. Controlled growth of silica shell on Ba0.6Sr0.4TiO3 nanoparticles used as precursors of ferroelectric composites. Chemistry of Materials, 2005, vol. 17, n° 17, p. 4530-4536. ⟨10.1021/cm050884r⟩. ⟨hal-00095754⟩