La0.7Na0.3−xKxMnO3 (x = 0.2): A thermistor film that exhibits high-sensitivity at room temperature

Abstract

A high-sensitivity thermistor La0.7Na0.3−xKxMnO3 (x = 0.2) film with a perovskite structure was fabricated and studied. The results show that the film displayed excellent adaptation and clear interfaces with the SrTiO3 substrate. Under the combination of Jahn–Teller effect and double exchange mechanism, the temperature coefficient of resistivity (TCR) of the La0.7Na0.1K0.2MnO3 film reached 10.86% K−1 at 296.98 K. Compared with the conventional VO2 and nickel–manganite-based film materials, the La0.7Na0.1K0.2MnO3 film with high TCR values at room temperature exhibited tunable metal–insulation transition temperature and more sensitive thermal properties. Consequently, the La0.7Na0.1K0.2MnO3 film can substantially improve the detection sensitivity of uncooled infrared bolometers as thermistor materials.