Enhanced magnetoresistance at room temperature in La_0.7Sr_0.3Mn_1 xSc_xO₃perovskites

Abstract

The uncommon Sc ions are employed to partially replace Mn in La0.7Sr0.3MnO3 perovskite. X-ray diffraction patterns indicate a pure single phase with rhombohedral lattice symmetry for La0.7Sr0.3Mn1−xScxO3 (0 ≤ x ≤ 0.1). The Curie temperature (TC) is tuned to near room temperature by Sc substitution with x = 0.03–0.05, and consequently a significant enhancement in magnetoresistance (MR) at room temperature is obtained in the Sc-doped compounds. Magnetic measurement shows no spin coupling between Sc and Mn ions. We suggest that the reduction in TC and the enhancement in MR are ascribable to the suppression of ferromagnetic order due to the structural distortion caused by the large Sc3+ ions.