On the magnetic behavior of polycrystalline RBaCo₂0_5+δ synthesized by solid state and wet chemical routes

In this paper, polycrystalline RBaCo₂O_5+δ (R = La, Y, Eu) samples were obtained through solid state reaction and polymeric precursor method. The crystalline quality of the samples was carefully evaluated by means of X-ray diffraction. Depending on the R cation, the main phases were characterized in a tetragonal P4/mmm, orthorhombic Pmmm or trigonal R-3c structure. The oxygen content, being a fundamental parameter in the studied system, was determined by iodometric tritration. While no stoichiometric oxygen content was determined, the value of 5 ended up being close to 0.5 for all the samples studied. VSM magnetization measurements were taken according to the zero field cooling protocol. The M(T) curves clearly shows the characteristic magnetic behavior of the cobaltate with stoichiometry 112. The temperature at which the paramagnetic-ferromagnetic-antiferromagnetic transition occurs varies with the cation R