Improved room-temperature TCR of La0.7Ag0.125K0.175MnO3 films by optimizing sintering temperatures

Abstract

Cation-doped perovskite manganite has unique electrical transport properties; therefore, it has attracted attention due to its promising applications in the field of uncooled infrared bolometers. For the bolometer applications, high temperature coefficient of resistivity (TCR) at room-temperature is essential for the perovskite materials. To investigate the effect of sintering temperature (Ts) on TCR and obtain high TCR values of manganite films at room temperature, La0.7Ag0.125K0.175MnO3 (LAKMO) films were prepared on the (001) SrTiO3 substrate at various Ts via sol–gel spin coating method. Using analysis of structure, morphology, ionic valence, and electrical transport properties, LAKMO films with better crystalline quality and larger TCR values were obtained at higher Ts. The TCR value of LAKMO films reached a maximum value (9.46 % K−1) and the TCR peak temperature (Tk) reached room-temperature (298.75 K) at Ts of 1000 °C, indicating that the material has great potential for the uncooled infrared bolometer applications.