Dielectric behaviour of metal-glass-ceramic nanocomposites containing a ferroelectric phase

Abstract

Glass-ceramics containing barium titanate have been prepared using a sol-gel route. By a reduction treatment of the materials (some of them ion exchanged) metal particles of nickel and silver respectively having diameters in the range 2.5 to 20 nm have been precipitated within them. Specimens prepared by hot compaction of the resultant powders show dielectric constant values varying from ~400 to 900 at a frequency of 1 kHz depending on the reduction schedule. Modified Bergman's model for a two-component composite dielectric has been tried without success to explain these results. An interrupted strand model appears to be relevant for these sample systems.