Preparation and characterization for LaMnO3 and 0.3LaMnO3–0.7Y2O3 high temperature bilayer structure NTC thermistors

This paper had reported a new conception about the bilayer negative temperature coefficient (NTC) thermistors ceramics. To be specific, the ceramics were constituted by two layers, among which, the perovskite-structured LaMnO 3 was used to maintain the NTC properties of the material, while the LaMnO 3 –Y 2 O 3 composite ceramic was selected due to its resistance. The bilayer NTC thermistors were successfully fabricated according to the classical uniaxial pressing method in this study. After sintering at 1350 °C for 6 h, the two layers could well integrate with each other, without any cracks. Moreover, the values of ρ 500 , B 500/900 constant and activation energy of the NTC thermistors were within the ranges of 2.20 × 10 5 –1.46 × 10 8 Ω cm, 6293–11218 K, 0.543–0.968 eV, respectively. Such ceramics would be suitable for the high temperature application of NTC thermistors.