Oxygen pressure and thickness dependent lattice strain in La0.7Sr0.3MnO3 films

We report magnetic and electronic properties of La0.7Sr0.3MnO3 (LSMO) thin films epitaxially grown on perovskite substrates by pulsed laser deposition, which are varied with oxygen background pressure and film thickness. The strains of the LSMO films are tuned by the two parameters but their resulting effects are somewhat different. The lattice strain induced by the oxygen pressure suppresses the ferromagnetic transition (T-C) and metal-insulator transition (T-MI) temperatures. With decreasing film thickness from 110 to 11 nm, however, small changes in both T-C and T-MI were observed. These results suggest that the physical properties of the LSMO films are strongly dependent on the oxygen content but less sensitive to the film thickness. (C) 2003 American Institute of Physics.