Magnetism and transport of Ln(0.5)Sr(0.5)CoO(3) (Ln = Pr, Nd, Sm and Eu)

Magnetism and transport have been investigated for perovskite cobalt oxides Ln(0.5)Sr(0.5)CoO(3) (Ln = Pr, Nd, Sm and Eu). The crystal structures are monoclinic (P2(1)/n) for Pr0.5Sr0.5CoO3, orthorhombic (Pnma) for Nd0.5Sr0.5 CoO3 and Sn0.5Sr0.5CoO3, and cubic (Pm3m) for Eu0.5Sr0.5CoO3. DC magnetizat ion measurements showed ferromagnetic transitions with Curie temperatures ( Tc) between 233 and 155 K. Metallic behavior was observed in resistivity-te mperature curves below 300 K. This is an entirely different property from t hat of Ln(0.5)Ba(0.5)CoO(3), which may be qualitatively explained in connec tion with the crystal structures. (C) 2001 Elsevier Science Ltd. All rights reserved.