Abstract
The Nd doping effect on the room temperature magnetoresistance in manganites (La1−xNdx)0.67Sr0.33MnO3 was investigated. With increasing Nd doping content in manganites (La1−xNdx)0.67Sr0.33MnO3 the room temperature magnetoresistance ΔR/R0 decreases for low Nd content x < 0.1, which may be mainly due to the sharp reduction of the room temperature saturation magnetization MS. For x > 0.1, an enhancement of the room temperature magnetoresistance can be obtained. Such enhancement of the room temperature magnetoresistance is correlated with the shift of the Curie temperature to near room temperature and the slow change of the room temperature saturation magnetization MS induced by the appropriate Nd doping. The ΔR/R0 become small again at large Nd doping contents. The drop of ΔR/R0 may be attributed to their lower metal-insulator transition temperature TMI far from the room temperature and the smaller MS value at room temperature. Values of the room temperature magnetoresistance ΔR/R0 for manganites (La1−xNdx)0.67Sr0.33MnO3 depend not only on the Curie temperature TC but also on the metal-insulator transition temperature TMI and the room temperature saturation magnetization MS.
