Comparison of the magnetization behavior in Nd and Sm substituted La0.7Pb0.3MnO3 systems

Abstract

AbstractIn this work, the magnetization behavior of two maganite oxide systems, La0.7–xNdxPb0.3MnO3 and La0.7–xSmxPb0.3MnO3, has been synthesized. The partial replacement of La ions by Nd or Sm results in a considerable decrease in the ferromagnetic ordering temperature TC. Moreover, clearly irreversible behavior in the field‐cooling and zero‐field‐cooling curves at a low applied field shows the short‐range spin order phase. These facts are in agreement with the smaller ionic radii of Nd (0.127 nm) and Sm (0.124 nm) ions in contrast to La ion (0.136 nm) with the corresponding larger distortion of perovskite structure. The saturation magnetization MS is increased as Nd content is increased which provides a relative contrast with the decrease of MS by the increase of Sm content. This can be interpreted in terms of the competition between the suppression of ferromagnetism due to structure tuning induced by the small ionic radius of the interpolated cation into the La‐site and the increase of ferromagnetic spins due to the introduction of magnetic Nd or Sm ions with f ‐shell electrons. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)