Low temperature fired dielectric ceramic composition with flat TC characteristic and method of making

A dielectric ceramic composition formed by firing a mixture comprising (a) from about 93.5 to about 96.5 percent by weight of a base ceramic preparation consisting essentially of metal oxides or precursors thereof in proportions to provide, in the oxide form, from about 98.0 to about 99 weight percent barium titanate, from about 0.97 to about 1.54 weight percent niobium pentoxide, and from about 0.19 to about 0.32 weight percent cobalt oxide;

• (b) from about 3.5 to about 6.5 percent by weight of a ceramic flux consisting essentially of metal oxides or precursors thereof in proportions to provide, in the oxide form, about 16 to about 60 weight percent bismuth titanate (Bi.sub.2 Ti.sub.2 O.sub.7), about 8 to about 52 weight percent lead titanate, about 18 to about 35 weight percent zinc oxide, and about 5 to about 11 weight percent boron oxide;
• and (c) manganese dioxide or precursors thereof in proportions to provide manganese dioxide in an amount of from about 0 to 0.114 percent of the combined weight of said base ceramic preparation and said ceramic flux.

A dielectric ceramic composition having a dielectric constant greater than 2400, said composition consisting essentially of from about 91.6 to about 95.5 weight percent barium titanate, from about 0.91 to about 1.49 weight percent niobium pentoxide, from about 0.18 to about 0.31 weight percent cobalt oxide, from about 1.04 to about 1.87 weight percent bismuth trioxide, from about 0.68 to about 1.23 weight percent titanium dioxide, from about 0.67 to about 1.20 weight percent lead oxide, from about 0.26 to about 0.46 weight percent boron oxide, from about 0.82 to about 1.49 weight percent zinc oxide, and from 0 to about 0.11 weight percent manganese dioxide, wherein the capacitance of said composition varies with temperature about 15 percent or less from the capacitance at 25.degree. C. at temperatures between about -55.degree. C. and about 125.degree. C.

A dielectric ceramic composition formed from (a) about 95.24 percent by weight of a base ceramic preparation consisting essentially of metal oxides or precursors thereof in proportions to provide, in the oxide form, about 98.31 weight percent barium titanate, about 1.40 weight percent niobium pentoxide, and 0.29 weight percent cobalt oxide;

• (b) about 4.76 percent by weight of a ceramic flux consisting essentially of metal oxides or precursors thereof in proportions to provide, in the oxide form, about 27.99 weight percent bismuth titanate (Bi.sub.2 Ti.sub.2 O.sub.7), about 40.02 weight percent lead titanate, about 24.4 weight percent zinc oxide and 7.6 weight percent boron oxide;
• and (c) manganese dioxide or precursors thereof in proportions to provide manganese dioxide in an amount of about 0.05 percent of the combined of the combined weight of said base ceramic preparation and said ceramic flux.