Ceramic composition with improved electrical and mechanical properties

摘要

A ceramic composition comprising a solid solution of the ternary system consisting essentially of lead magnesium-nio­bate (Pb(Mg_1/3Nb_2/3)O₃), lead nickel-niobate (Pb(Ni_1/3Nb_2/3)O₃) and lead titanate (PbTiO₃) as a major constituent, and an additional constituent consisting essentially of lead manga­nese-niobate (Pb(Mn_1/3Nb_2/3)O₃). The ternary system is expressed by the general formula [Pb(Mg_1/3Nb_2/3)O₃]_x-­[Pb(Ni_1/3Nb_2/3)O₃]_y-[PbTiO₃]_z wherein the subscripts x, y and z satisfy the equation x+y+z=1 and fall within the region defined by the line segments joining the seven points A, B, C, D, E, F and G within the triangular ternary-system diagram shown in the accompanying drawing. Preferably, the lead manganese-niobate (Pb(Mn_1/3Nb_2/3)O₃) is contained in a propor­tion of 0.01 mol% to 10 mol% to the major constituent.