Pulsed-laser crystallization and epitaxial growth of metal-organic films of Ca-doped LaMnO_3 on STO and LSAT substrates

摘要

Ca-doped LaMnO_3 (LCMO) thin films have been successfully prepared on SrTiO_3 (STO) and [(LaAlO_3)_(0.3)-(SrAlTaO_6)_(0.7)] (LSAT) substrates using the excimer laser assisted metal-organic deposition (ELAMOD) process. The crystallization and the epitaxial growth of the amorphous metal-organic LCMO thin films have been achieved using a KrF excimer laser irradiation while the substrates were kept at constant temperature of 500℃. Epitaxial films were obtained using laser fluence in the interval of 50-120 mJ/cm~2. The microstructure of the LCMO films was studied using cross-section transmission electron microscopy. High quality of LCMO films having smooth surfaces and sharp interfaces were obtained on both the STO and the LSAT substrates. The effect of the laser fluence on the temperature coefficient of resistance (TCR) was investigated. The largest values of TCR of the LCMO grown on the LSAT and the STO substrates of 8.3% K~(-1) and 7.46% K~(-1) were obtained at different laser fluence of 80 mJ/cm~2 and 70 mJ/cm~2, respectively.