Patent Number: 8,067,325

Title: Semiconductor ceramic composition

Abstract: It is intended to provide a semiconductor ceramic composition containing no Pb, which is capable of shifting the Curie temperate to a positive direction as well as of controlling room temperature resistivity and having an excellent jump characteristic. Since the semiconductor ceramic composition in which a portion of Ba of BaTiO.sub.3 is substituted by Bi--Na has a crystal in which a central part and an outer shell part of a crystal grain are different from each other in composition, the composition is capable of improving control of room temperature resistivity and a jump characteristic, and therefore it is optimum as a material for a PTC thermistor, a PTC heater, a PTC switch, a temperature detector, and the like.

Inventors: Shimada; Takeshi (Saitama, JP), Toji; Kazuya (Osaka, JP)

Assignee: Hitachi Metals, Ltd.

International Classification: C04B 35/00 (20060101)

Expiration Date: 2020-11-29 0:00:00