Crystal structures and scaling behaviors of (La1-xPbx)MnO3 and La0.7(Ba1-xPbx)0.3CoO3 systems with x = 0-0.5

[[abstract]]The magnetic properties and scaling behaviors in both series La1-xPbxMnO3 and La0.7(Ba1-yPbx)0.3CoO3 with x = 0.0-0.5 were studied. All samples crystallize in a rhombohedral R3C space group with a∼ 0.54 nm and c∼ 1.33 nm. The Pb2 substitution for La3+ in the (La1-xPbx)MnO3 system induces a mixed-valence state of Mn ions. The ferromagnetic transition temperature TC increases with increasing Pb content from 225 K for x = 0 to 355 K for x = 0.5 in the (La1-xPbx)MnO3 series. For La0.7(Ba1-xPbx)0.3CoO3 samples the magnetic transition temperature is not significantly affected by the replacement of Pb ions for Ba2+ ion and keep at about 200 K due to the constant ratio of Co4+/Co3+. All the samples exhibit the canonical spin-glass behaviors as well as the scaling behaviors.[[fileno]]2010141010038[[department]]物理