Hydrothermal process for making barium titanate powders

Abstract

A hydrothermal process for making barium titanate powders. The process utilizes a thawed hydrated titanium oxide gel as a titanium source for the hydrothermal reaction. The process includes mixing the thawed hydrated titanium oxide gel and a barium source in a reaction chamber to form a hydrothermal reaction mixture. The temperature of the hydrothermal reaction mixture in the reaction chamber is increased to a reaction temperature to form a barium titanate particle suspension. The particle suspension is then cooled to room temperature. The resulting barium titanate particles, preferably, have a submicron particle size.

Description

Background of the invention [0001] The present invention relates to the method for preparing barium titanate, more specifically, relates to the method for preparing barium titanate powder by hydrothermal method. [0002] Barium titanate has a high dielectric constant, which makes it a useful material in the fabrication of multilayer ceramic capacitors ("MLCs"). It can be used in doped form as a dielectric material in MLC applications. MLCs include alternating dielectric and conductive materials. The dielectric layer of MLC is usually made from a high solids dispersion that usually includes barium titanate powder and a polymer binder in an aqueous or non-aqueous solvent. The dispersion or slurry is cast or coated to form ceramic dielectric "green" layers, and then conductive material is applied in a pattern and stacked to form alternating green ceramic dielectric layers and conductive Floor. The laminate is cut into MLC-sized cubes, the cubes are heated to remove organics s...

AI Technical Summary

Problems solved by technology

Improper use of various secondary treatments can produce agglomerated powders, which are unsuitable for ultra-thin layers and powder surfaces with non-stoichiometric Ba / Ti due to barium incompatibility

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