Low field anisotropic colossal magnetoresistance in $Sm_{0.53} Sr_{0.47} Mn O_3$ thin films

摘要

SSMO5347 thin films (thicknesses ~200 nm) were deposited by on-axis dcmagnetron sputtering on the single crystal LSAT (001) substrates. These filmsare oriented along the out of plane c-direction. The ferromagnetic andinsulator-metal transition occurs at 96 K and 91 K, respectively. Themagnetization easy axis is observed to lie in the plane of the film while themagnetic hard axis is found to be along the normal to this. Themagnetotransport of the SSMO films, which was measured as a function of angle(theta) between the magnetic field (H) and plane of the film, shows colossalanisotropy. Magnetoresistance (MR) decreases drastically as theta increasesfrom 0 degree (H//easy axis) to 90 degree (H//hard axis). The out-of-planeanisotropic MR (AMR) is as high as 88 % at H=3.6 kOe and 78 K. The colossalanisotropy has been explained in terms of the magnetic anisotropies at play andthe magnetic domain motion in applied magnetic field.