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

Abstract

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 LaMnO3 was used to maintain the NTC properties of the material, while the LaMnO3–Y2O3 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 ρ500, B500/900 constant and activation energy of the NTC thermistors were within the ranges of 2.20 × 105–1.46 × 108 Ω cm, 6293–11218 K, 0.543–0.968 eV, respectively. Such ceramics would be suitable for the high temperature application of NTC thermistors.