Influence of the substitution of Sm, Gd, and Dy for La in La0.7Sr0.3MnO3 on its magnetic and electric properties and strengthening effect on room-temperature CMR

A series of La0.7–xSmxSr0.3MnO3, La0.7–xGdxSr0.3MnO3, and La0.7–xDyxSr0.3MnO3 (x=0.00, 0.10, 0.20, 0.30) samples were prepared by the solid-state reaction method. The influence of the substitution of Sm, Gd, and Dy for La on the magnetic and electric properties and on the magnetoresistance (MR) was studied through measurements of M-T curves and ρ-T curves. The results showed that: lattice distortion induced by substitution of Sm, Gd, and Dy for La and extra magnetism of substitution had great influence on the magnetic and electric properties of perovskite manganites; substitution of magnetic rare earth element for La was an effective way to change Curie temperature and to strengthen MR in perovskite manganites; and appropriate substitution proportion would generate large MR near room temperature.