Thickness-dependent magnetic and transport properties of La0.5Sr0.5MnO3 thin films deposited by DC magnetron sputtering on the LaAlO3 substrate

Abstract

Thickness-dependent structural, magnetic and transport properties of La0.5Sr0.5MnO3 (LSMO) thin films have been studied. A series of the LSMO films with thickness 30, 60, 125 and 300?nm have been deposited on the LaAlO3 substrate using DC magnetron sputtering. The paramagnetic to ferromagnetic transition at TC is followed by antiferromagnetic ordering at TN in all films. It is also found that all LSMO films have TC lower than that of bulk LSMO. A small variation of TC is observed on increasing the film thickness. However, TN is found to rise with increase in the film thickness. The 60?nm-thick film shows a wide insulator to metal transition. The resistivity above 240?K of the films with various thicknesses is consistent with a small polaronic hopping conductivity. The polaronic formation energy EA rises with the increase of the film thickness except for 60?nm thin film, where a small decline in EA is observed. The correlation between observed structural, magnetic and electrical properties with the thickness of the films has been discussed in this paper. ? 2017, Springer-Verlag GmbH Germany, part of Springer Nature.