Eminent room-temperature temperature coefficient of resistivity in La0.76Ba0.24MnO3/LaAlO3 films

Herein, the electrical transport properties of La _0.76Ba _0.24MnO ₃(LBMO) films were investigated by preparing LBMO films using the sol-gel method and varying the sintering temperature. The results show that the surface morphology of the films exhibits a homogeneous and compact microstructure, characterized by a three-dimensional island-like growth pattern, which remains consistent across various sintering temperatures. The LBMO film exhibits a crystal structure of R 3 ̅ c in the sintering temperature ( T _s) range of 1373–1448 K. With the increasing of T _s, the full width at half maximum of the diffraction peaks {012}, {024} and {312} of the LBMO films gradually decreases, meaning the films crystallinity is significantly improved. At the same time, the internal strain of the LBMO films decreases, resulting in the change of the MnO ₆ octahedron, and has an impact on the electronic transition and the electron-phonon coupling. The DE mechanism is increase and then decrease with increasing T _s. With the increase of T _s, the metallicity of the film samples decreases, and the insulating property increases, the overall change of the metal-insulator transition temperature ( T _p) of the film samples is not significant, the resistivity firstly decreases and then increases; T _k slightly decreases, the peak TCR firstly increases and then decreases, and when T _s = 1398 K, T _k = 298.14 K, the TCR reaches the maximum value of 10.20 % K ^-1. The results show that the change of the sintering temperature can obtain a high value of the room-temperature TCR.