Grain size reduction effect of barium titanate embedded in silica xerogel

Grain size reduction of barium titanate embedded in silica xerogel was observed using Raman spectroscopy, differential thermal analysis, atomic force microscopy and X-ray diffraction with Rietveld refinement. We compare the structural properties of pure barium titanate samples and those embedded in an inorganic matrix. The pure powders and the composites were in tetragonal phase with cell parameters a = 3.9951 Å, c = 4.0274 Å, and a = 3.9955 Å, c = 4.0286 Å, respectively. The main structural effect is the grain size diminishing due to the interaction between the barium titanate particles and the inorganic matrix. A consequence of grain size reduction is the reduction of Curie temperature for the powder embedded in silica xerogel in comparison with the pure powders, from 116 °C to 95 °C. © 2008 Elsevier B.V. All rights reserved.

Crystal structure; Electronic material; Xerogels Atomic force microscopy; Crystal structure; Differential thermal analysis; Grain size and shape; Raman spectroscopy; Silica; Xerogels; Cell parameters; Electronic materials; Grain size reduction; Inorganic matrix; Barium titanate

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