Effect of different post-annealing durations on electromagnetic properties of La0.67Ca0.33MnO3:Ag-0.2 thin films prepared by pulsed laser deposition

摘要

La0.67Ca0.33MnO3:Ag-0.2 thin films were obtained by pulsed laser deposition followed by post-annealing at 1200 degrees C for varied durations. Surface morphologies, structures, and electrical and magnetic properties of films prepared with different annealing durations were significantly different. X-ray diffraction results showed that annealed films exhibited stronger diffraction peaks and C-axis preferred growth. Regarding their electrical properties, metal-insulator transition temperature (T-MI) and temperature coefficient of resistance (TCR) increased first and then decreased with the increase in annealing duration. In terms of their magnetic properties, thin films displayed ferromagnetic-paramagnetic transition. With the increase in annealing duration, Curie temperature increased first and then decreased. Specifically, the film annealed for 3 h showed excellent electromagnetic properties, with relatively high TCR of 20.3%.K-1 and near room temperature T-MI of 285.7 degrees C. Owing to these excellent properties, as-prepared thin films have application potential in infrared detectors.