US 4,054,531 A · Ceramic dielectric composition

Abstract

A ceramic dielectric composition is provided which consists essentially of bismuth titanate with substituents, expressed by the formula: Bi.sub.4-x Me.sub.x Ti.sub.3-y R.sub.y O.sub.12 where R is at least one divalent metal selected from strontium, barium and lead, Me is at least one pentavalent metal selected from tantalum, niobium and antimony, and both x and y are numbers falling within the range of 0.4 to 2.0 and the ratio of x/y is within the range of 0.9 to 1.1. This composition may contain specified metal oxide additives. The ceremic dielectric composition is sintered at a relatively low temperature, and exhibits a dielectric constant having a reduced dependence upon temperature variations over a wide use range, a reduced dielectric loss, enhanced resistivity and breakdown voltage.

Claims9

Dependent claims

A ceramic dielectric composition consisting essentially of ( 1) bismuth titanate with substituents, expressed by the formula:

Bi.sub.4-x Me.sub.x Ti.sub.3-y R.sub.y O.sub.12
where Me is at least one divalent metal selected from the group consisting of strontinum, barium and lead, R is at least one pentavalent metal selected from the group consisting of tantalum, niobium and antimony, and both x and y are numbers falling within the range of 0.4 to 2.0 and the ratio of x/y is within the range of 0.9 to 1.1, and;
(2) at least one metal oxide selected from the group consisting of tungsten oxide and molybdenum oxide in an amount of 0.01 to 2.0% by weight based on the weight of the aforesaid component (1) of the formula Bi.sub.4-y Me.sub.x Ti.sub.3-y R.sub.y O.sub.12 and expressed in terms of the amount of tungsten trioxide (WO.sub.3) and molybdenum trioxide (MoO.sub.3), respectively.

Dependencies are inferred from the claim text.

Ceramic dielectric composition

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Ceramic dielectric composition

Life of this patent

Abstract

Claims9