Neutron diffraction and magnetic study of the Nd0.7Pb0.3Mn1−xFexO3 (0⩽x⩽0.1) perovskites

The effect of Fe doping on the ferromagnetic Nd0.7Pb0.3Mn1−xFexO3 (image, 0.025, 0.05, 0.075, 0.1) phases has been studied in order to analyze the double-exchange interaction. The structural and magnetic study has been carried out by neutron powder diffraction and susceptibility measurements between 1.7 and 300 K. The substitution of Fe at the Mn site results in reductions in both the Curie temperature Tc and the magnetic moment per Mn ion without appreciable differences in the crystal structures. All the compounds crystallize in image space group. The thermal evolution of the lattice parameters of the Nd0.7Pb0.3Mn1−xFexO3 (image, 0.05, 0.075) compounds shows discontinuities in volume and lattice parameters close to the magnetic transition temperature. Increasing amounts of Fe3+ reduces the double exchange interactions and no magnetic contribution for image is observed. The magnetic structures of Nd0.7Pb0.3Mn1−xFexO3 (image, 0.025, 0.05, 0.075) compounds show that the Nd and Mn ions are ferromagnetically ordered.