Facile high-performance film thermocouple made of strontium lanthanum chromate for temperature sensing in air

Film thermocouples as the most effective tool are used to monitor the real-time and accurate in situ temperature in harsh environment, which will demand their electrodes with high thermal-resistant properties, high sensitivity, and stability. In this work, a series of solid solutions based on strontium lanthanum chromate were systematically investigated as new electrodes. LaCrO₃ and La_0.8Sr_0.2CrO₃ with some glass additives were chosen to fabricate high-performance thick-film thermocouple due to a bigger Fermi level difference between them. The thermocouple shows a high sensitivity (107.8 μV/°C) during static calibration, and an excellent reproducibility and stability during multicycle calibrations carried out up to 1550°C, resulting in a record ultra-high temperature sensing in film thermocouples. This facile thermocouple may open up a new way to measure high temperature in air or oxidation atmosphere accurately.