Capacitor dielectric with inner blocking layers and method for producing the same

Claim 1

A capacitor dielectric with inner blocking layers, comprising: (a) a polycrystalline ceramic body made of a material with a perovskite structure on the basis of barium titanate having the general formula ##EQU2## with M II selected from the group Ca, Sr, Pb and Mg and M IV = Zr, Sn, with z assuming the values 1.005 to 1.05; (b) said dielectric containing at least two different doping substances of which one selected from the group antimony, niobium, lanthanum and bismuth is inside crystallites of the crystalline body and causes predominantly n-type conduction, and the other selected from the group copper, cobalt, nickel, iron and manganese in the surface layer of the crystallites causes predominantly p-type conduction, the proportion of the doping substance causing the n-type condution being 1.5 to 2.5 times greater than a maximum doping amount (maximum solid state solubility) and the proportion of the substance causing the p-type conduction amounting to 0.01 to 0.15% by weight; (c) a titanate intermediate phase disposed between grains of the crystallites which is rich in titanium dioxide and is at least partially recrystallized and contains the doping substance causing p-type conduction spread inhomogeneously such that this p-type doping substance is highly enriched towards the crystallite grain surfaces.