Effect of the A Cation Size on the Structural, Magnetic, and Electrical Properties of Perovskites (La1-xNdx)0.7Sr0.3r003nMnO3

An intense effort has recently been devoted to studying the interplay between structure, magnetism, and transport in manganese perovskite Ln1-xAxMnO3 (Ln=La, Pr, Nd, Sm; A=Ca, Ba, Sr). As a function of temperature, applied magnetic field, doping, A-site ionic radius , and A-site size disorder, this system displays a rich phase diagram for both magnetotransport and structural properties. We have investigated the structural, magnetic, and transport properties of (La1-xNdx)0.7Sr0.3MnO3. The crystal structure was examined by X-ray powder diffraction which indicated that all the samples were single phase and revealed a transition from rhombohedral to orthorhombic structure with increasing x. The magnetization and resistivity investigation shows that for all values of x, (La1-xNdx)0.7Sr0.3MnO3 are ferromagnetic–metallic at low temperatures and paramagnetic–semiconductor above the Curie temperature Tc.