Semiconducting ceramic composition having positive temperature coefficient of resistance and production process thereof
AssigneeTDK Corporation
InventorKouji Hayashi
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Abstract
A semiconducting ceramic composition having a positive temperature coefficient and a process for production thereof. The semiconducting ceramic composition comprises a barium titanate semiconducting ceramic composition containing silicon oxide and manganese, the semiconducting ceramic composition further comprising sodium in an amount of from 0.0005 to 0.02 wt % based on the amount of the barium titanate semiconducting ceramic composition.
Claims20
A semiconducting ceramic composition having a positive temperature coefficient, comprising barium, oxygen, titanium, silicon, manganese and a semiconducting material element, having a molar ratio of Ba:O of 0.4:3 to 0.999:3, Ti:O of 0.995:3 to 1.03:3, an amount of silicon, as silicon oxide, of 0.2 to 1.0 wt.%, an amount of manganese of 0.002 to 0.04 wt.%, and an amount of sodium of 0.0005 to 0.02 wt.%.
A process for producing a semiconducting ceramic composition having a positive temperature coefficient, comprising:
- calcining starting materials to produce a composition comprising barium, oxygen, titanium, silicon, manganese and a semiconducting material element, having a molar ratio of Ba:O of 0.4:3 to 0.999:3, Ti:O of 0.995:3 to 1.03:3, an mount of silicon, as silicon oxide, of 0.2 to 1.0 wt.%, and an amount of manganese of 0.002 to 0.04 wt.%;
- adding a sodium compound to said composition in such an amount that the sodium content is from 0.0005 to 0.02 wt.%;
- and
- sintering said composition.
Dependencies are inferred from the claim text.