Magnetic and transport properties of half-metallic ferromagnetic compounds as the La0.7Sr0.3MnO3 epitaxial manganite oxide thin films

Abstract

The aim of this study is to investigate magnetic properties of an example of half-metallic and ferromagnetic compounds, namely, the La0.7Sr1.3MnO3 (LSMO) epitaxial manganite oxide thin films using tensile SrTiO3 (STO) and compressive LaAlO3 (LAO) substrates. From the magnetic measurements, it can be shown a large magnetic anisotropy in these compounds. The plane of the film is the easy magnetization direction for LSMO deposited onto STO substrate. Also, it seems that the magnetic properties are quite influenced by the strain effects in the films. Furthermore, electrical resistivity and magnetoresistance measurements were performed. The residual resistivity is higher than the massive single crystal sample value due certainly to the crystal defects. The half-metallic character of the LSMO films is not modified when the temperature increases. The magnetoresistance is only strong close to the Curie temperature and substantial in high magnetic field. And these are typical of the colossal magnetoresistance (CMR). © 2008 Asian Network for Scientific Information.