Patent ID: 6939822
Filing Date: 2005-09-06
Classification: B32B,C04B,H01G

Abstract:
1. A method for making a dielectric ceramic having a ceramic structure comprising crystal grains and grain boundaries between the crystal grains, the crystal grains comprising a main component represented by the formula ABO 3 in which the average rare earth element concentration in the interior of the crystal grains is about 50% or less of the average rare earth element concentration at the grain boundaries, and about 20% to 70% of the crystal grains, by number, have a rare earth element concentration in the center of the crystal grain of at least about 1/50 of the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain, comprising: mixing AO, BO mixing AO and BO mixing the modified ABO wherein A is barium or barium and at least one of calcium and strontium, and B is titanium or titanium and at least one of zirconium and hafnium.