SEMICONDUCTOR CERAMIC COMPOSITION, METHOD FOR PRODUCING SAME, PTC ELEMENT AND HEAT GENERATING MODU

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Disclosed is a BaTiO3 semiconductor ceramic composition which has low room temperature resistivity, small change over time and excellent jump characteristics. Specifically disclosed is a semiconductor ceramic composition which has a composition formula of [(Biθ-Naδ)x(Ba1-yRy)1-x]TiO3 (wherein R represents at least one rare earth element), with x, y, θ and δ in the formula satisfying 0 < x ≤ 0.3, 0 < y ≤ 0.02, 0.46 < θ ≤ 0.62 and 0.45 < δ ≤ 0.60 and the molar ratio of Bi to Na in a sintered body, namely Bi/Na being more than 1.02 but 1.20 or less. Also specifically disclosed is a method for producing a semiconductor ceramic composition, wherein the materials are weighed so that the molar ratio Bi/Na is within the range of 1.05-1.24 in a step for preparing a (BiNa)TiO3 calcined powder or a Bi material powder is added when a mixed calcined powder is prepared so that the molar ratio Bi/Na is within the range of 1.04-1.23 in order that the sintered body is able to have the above-described composition formula.