High temperature NTC ceramic resistors (ambient–1000 °C)

• Published in: Journal of the European Ceramic Society 2004, Vol.24 (6), p.1237-1241
• Main Authors: Houivet, David, Bernard, Jérôme, Haussonne, Jean-Marie
• Format: Article
• Language: English
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Conductors, resistors (including thermistors, varistors, and photoresistors); Electrical properties; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Electrotechnical and electronic ceramics; Exact sciences and technology; NTC; Perovskites; Technical ceramics; Thermistors; Y 2O 3
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(03)00376-5

New temperature sensors operating from ambient to 1000 °C, stable in diesel exhaust gas, and cheap, are needed. Such components may be ceramics. The value of their electrical resistance versus temperature is classically expressed as R= a.exp( B/ T). Compounds from the ternary diagram Y 2O 3–Mn 2O 3–Cr 2O 3 may permit the obtaining of such performances. We have synthesized some compositions by solid-state reaction. Dense ceramics sintered at 1600 °C are two-phased, compound of a Y 2O 3 phase and an orthorhombic perovskite YCr 0.5Mn 0.5O 3 phase. Their resistivity at room temperature can be in the range 4 kΩ cm to 10 6 MΩ cm together with a B coefficient value of about 3600 K. Such ceramics can be used to make NTC resistors with a resistance value ranging from some hundreds kΩ at room temperature to some Ω at 1000 °C.