Dielectric composite materials and method for preparing

摘要: The invention allows the fabrication of small, dense beads dielectric materials with selected compositions, which are incorporated into a polymeric matrix for use in capacitors, filters, and like. A porous, generally spherical bead hydrous metal oxide containing titanium or zirconium is made by sol-gel process to form substantially rigid having fine crystallite size correspondingly finely distributed internal porosity. resulting gel may be washed hydrothermally reacted soluble alkaline earth salt (typically Ba Sr) at elevated temperature pressure convert mixed titanium- zirconium-alkaline while retaining shape. Alternatively, coprecipitation. This then washed, dried calcined produce desired (BaTiO3, PbTiO3, SrZrO3) structure. sintered polymer matrix. composite material electrically “poled” if desired.