Monolithic ceramic capacitors

Claim 2

A ceramic dielectric material for use with base metal electrodes in a ceramic capacitor comprising: from 85 to 88 mole percent barium titanate (BaTiO 3 ); 4 to 5 mole percent barium oxide (BaO); 1 to 1.5 mole percent magnesium ortho-titanate; 3 to 4.5 mole percent calcium titanate (CaTiO 3 ); and 3 to 4.5 mole percent of a zirconate selected from the group consisting of barium, calcium and strontium.

Claim 3

A ceramic dielectric material for use with base metal electrodes to form a ceramic capacitor comprising: 86.76 mole percent barium titanate; 4.6 mole percent barium oxide; 1.18 mole percent magnesium ortho-titanate (Mg 2 TiO 4 ); 3.77 mole percent calcium titanate; and 3.64 mole percent strontium zirconate.

Claim 4

A ceramic dielectric material for use with base metal electrodes to form a ceramic capacitor comprising: 86.76 mole percent barium titanate; 4.6 mole percent barium oxide; 1.18 mole percent magnesium ortho-titanate (Mg 2 TiO 4 ); 3.77 mole percent calcium titanate; and 3.64 mole percent strontium zirconate.

Claim 5

A process of preparing ceramic capacitors comprising the steps of: wet milling a mixture of powders consisting of 85 to 88 mole percent barium titanate, 4 to 5 mole percent barium oxide, 1 to 1.5 mole percent magnesium ortho-titanate (Mg 2 TiO 4 ), 3 to 4.5 mole percent calcium titanate, and 3 to 4.5 mole percent barium, strontium or calcium zirconate; pressing the wet milled powders into capacitor blanks; applying nickel or cobalt electrodes to the blanks; and firing the blanks at a temperature between 1360° and 1390° C in an atmosphere of nitrogen containing from 2 to 10 mole percent water.

Claim 6

A process of preparing ceramic capacitors comprising the steps of: wet milling a mixture of powders consisting of 85 to 88 mole percent barium titanate, 4 to 5 mole percent barium oxide, 1 to 1.5 mole percent magnesium ortho-titanate (Mg 2 TiO 4 ), 3 to 4.5 mole percent calcium titanate, and 3 to 4.5 mole percent barium, strontium or calcium zirconate; pressing the wet milled powders into capacitor blanks; applying nickel or cobalt electrodes to the blanks; and firing the blanks at a temperature between 1360° and 1390° C in an atmosphere of nitrogen containing from 2 to 10 mole percent water.

Claim 7

The process of claim 3 wherein the mixture comprises: 86.76 mole percent barium titanate; 4.6 mole percent barium oxide; 1.18 mole percent magnesium ortho-titanate; 3.77 mole percent calcium titanate; and 3.64 mole percent strontium zirconate.

Claim 8

The process of claim 3 wherein the elements of water in the nitrogen atmosphere are present as hydrogen and carbon dioxide.

Claim 9

The process of claim 3 wherein the capacitor blanks are fired at a temperature between 1370° and 1380° C for a period of eight hours.

Claim 10

A ceramic capacitor comprising: at least two base metal electrodes; and a dielectric material intermediate said electrodes and consisting of 86.76 mole percent barium titanate, 4.6 mole percent barium oxide, 1.18 mole percent magnesium ortho-titanate (MgTiO 4 ), 3.77 mole percent calcium titanate, and 3.64 mole percent strontium zirconate.

Claim 11

A ceramic capacitor comprising: at least two base metal electrodes; and a dielectric material intermediate said electrodes and consisting of 86.76 mole percent barium titanate, 4.6 mole percent barium oxide, 1.18 mole percent magnesium ortho-titanate (MgTiO 4 ), 3.77 mole percent calcium titanate, and 3.64 mole percent strontium zirconate.

Claim 12

The capacitor of claim 7 wherein said electrodes are selected from the group consisting of nickel and cobalt.