Synthesis and Magnetic Characterization of the La0.6Ln0.1Pb0.3MnO3(Ln=Pr,Nd, and Y) Manganites

[[abstract]]La0.6Ln0.1Pb0.3MnO3(Ln=Pr,Nd, and Y) oxides have been synthesized by a standard ceramic fabrication method. The partial replacement of La ions by small amounts of Pr, Nd, or Y ions results in a considerable decrease in the ferromagnetic transition temperature and clearly irreversible behavior in the field-cooling–zero-field-cooling curve at low field, showing a short-range spin order phase. These facts are in agreement with the smaller ionic radii of Pr, Nd, and Y ions in contrast to La ions, and the corresponding larger distortion of perovskite structures. The hysteresis loops of these samples illustrate that the magnetization still remains unsaturated in high field and the saturation moments are larger for Pr-doped and Nd-doped manganites. This can be interpreted in terms of canted spins between Mn ions and magnetic Pr or Nd ions with f-shell electrons