Intermediate-temperature sensors based on La0.5Ba0.5MnO3/nanoporous anodic aluminum oxide multilayered film thermistors

Abstract

Perovskite La_0.5Ba_0.5MnO₃ (LBMO) film thermistors for temperature monitoring over a wide range of intermediate temperatures (200–450 °C) were fabricated on thin Al-foil substrates with a nanoporous anodic aluminum oxide layer at the Al surface (AAO-Al). Al₂O₃ nanoflake arrays were additionally grown on the AAO-Al using a pore-sealing process. The LBMO films were fabricated at 400 °C using the photoreaction of nanoparticles method with KrF laser irradiation. The obtained LBMO films were well crystallized using a laser fluence of 30 mJ cm⁻² and 500 pulses owing to the controlled photothermal heating effect. The multilayered LBMO/AAO-Al film thermistors exhibited an optimized thermistor constant of B = 2626 K over a wide range of temperatures (20–450 °C) and a very rapid response. The polycrystalline grains of the LBMO films were well integrated with the Al₂O₃ nanoflake arrays on the AAO-Al substrates, affording remarkably stable structural and thermistor properties of the LBMO/AAO-Al film thermistors during 1000 cycles of temperature cycling between room temperature and 400 °C.