Effect of deposition time on electrical properties of La0.67Ca0.33MnO3:Ag0.2 thin films by pulsed laser deposition

LCMOA (La0.67Ca0.33MnO3:Ag0.2) thin films were prepared on LaAlO3 (LAO) single-crystal substrates via pulsed laser deposition (PLD) technique deposited at different time. The resistance temperature (R–T) of the film was measured by a standard four-probe method, and the metal–insulation transition temperature (Tp) and temperature coefficient of resistance (TCR) corresponding to the peak resistance increase first and then decrease with the deposition time increasing. At t = 10 min, TCRmax = 14.05%·K−1, Tp = 292.2 K, the value is very close to room temperature 297 K. The pulse laser energy of 300 mJ was used to test the films with different deposition time. The peak value of laser-induced voltage (LIV) signal (Up) increased first and then decreased with the deposition time increasing. When t = 10 min, the Up value reached the maximum. Based on the above experimental results, the film with uncooled infrared detector application can be prepared by appropriate deposition time.