Synthesis, characterization, magnetism and transport properties of Nd1-xSrxCoO3 perovskites

We have prepared polycrystalline, single-phase Nd1-xSrxCoO3 materials (0 le ss than or equal tox less than or equal to0.40) using the nitrate decomposi tion method and we have studied how their structural, magnetic and transpor t properties change upon Sr2+ doping. In this context we find that these se ries of compounds crystallize in GdFeO3-type perovskite structures whose ce ll volume increases as x gets higher. From the magnetic point of view, this doping makes the materials evolve towards a ferromagnetic behavior as x in creases, so that for x > 0.20 the samples are already ferromagnetic below a T(c)similar to 225 K. Also, their electrical conductivity progressively in creases with x. Nevertheless the materials remain semiconducting for x less than or equal to0.30 and only the sample with x=0.40 displays a MI transit ion as a function of temperature (T(MI)similar to 160 K). (C) 2001 Elsevier Science B.V. All rights reserved.