Murata Manufacturing Co., Ltd.

Yoichi Kawase

Hideaki Niimi

Akinori Nakayama

Terunobu Ishikawa

Satoshi Ueno

Masahiko Kawase

Yasuhiro Nabika

Yoshiyuki Yamashita

Yuichi Hirata

Makoto Matsubara

Syunsuke Okuda

A barium titanate-based semiconductor ceramic composition which can be used for PTC thermistors for temperature sensors and which has characteristics, including a linear characteristic, advantageous for such PTC thermistors and a barium titanate-based semiconductor ceramic device. The barium titanate-based semiconductor ceramic composition is represented by the formula (BaMeSr)TiO+ySiO, wherein Me is at least one of Er, Sm, Ce, and La, 0.001&#x2266;v&#x2266;0.005, 0.42&#x2266;w&#x2266;0.49, 0.99&#x2266;x&#x2266;1.03, and 0.002&#x2266;y&#x2266;0.030.

Barium titanate-based semiconductor ceramic composition and barium titanate-based semiconductor ceramic device

A semiconductive ceramic is produced by sintering a semiconductive ceramic material containing a mixed powder of a lanthanum compound and a cobalt compound. The mixed powder has a specific surface area of about 3 m /g or more, an average primary particle size of about 2.0 &mgr;m or less, and an average secondary particle size of about 10 &mgr;m or less.

Semiconductive ceramic material, semiconductive ceramic, and semiconductive ceramic element

A semiconductor ceramic device includes a semiconductor ceramic sintered body and external electrodes. The semiconductor ceramic sintered body contains a lanthanum cobalt type oxide major component, about 0.1 to 10 mol % on an element conversion basis of an oxide of Cr as a sub-component, and about 0.001 to 0.5 mol % on an element conversion basis of at least one of the oxides of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ni, Cu and Zn.

Lanthanum cobalt oxide semiconductor ceramic and related devices

A semiconductive ceramic in which the B constant is maintained at about 4000 K or more at elevated temperature to thereby decrease power consumption, and the B constant is lowered less than 4000 K at low temperature so as to avoid unnecessary increase of resistance; as well as a semiconductive ceramic element using the same. The semiconductive ceramic is formed of a lanthanum cobalt oxide, which serves as the primary component, and, as a secondary component, at least one oxide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ni, Cu and Zn. The semiconductive ceramic element is fabricated through use of the semiconductive ceramic and an electrode formed thereon.

Semiconductive ceramic and semiconductive ceramic element using the same

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Yoichi Kawase