Ceramic dielectric with dielectric constant 40-1500 - made from barium titanate contg. aluminium, iron and/or zinc

摘要

Ceramic dielectric matl. with low temp.-dependence of the dielectric constants, based on barium titanate contg. iron and/or zinc, the novelty being that the matl. also contains aluminium. The amt. of Al, by wt. is pref. 2-27% esp. 4-5% with 0.05-0.5% Fe, or 0.6-1.2% Zn, opt. with 1-2% Fe. The pref. process consists of making a stoichiometric mit mixt. of BaCO3 and TiO2 and adding Fe2O3 and/or ZnO, plus Al2O3, mixing with water, then removing the water and heating at 1000 degrees C., followed by milling, mixing with an org binder, pressing in a die and sintering at 1260-1320 for min. 15 mins. Matl. has low dependence on both temp. and frequency and a low loss factor.