Doping effects on the magnetic properties of La_(0.5)Ba_(0.5)Co_(1-X)Ti_xO_3

摘要

A detailed magnetic study has been carried out for Ti-doped La_(0.5)Ba_(0.5)Co_(1-X)Ti_xO_3 (x = 0, 0.05, 0.5, 0.10, 0.125, and 0.15) cobaltites. Ti doping suppresses the ferromagnetic interaction in La_(0.5)Ba_(0.5)CoO_3 and induces an antiferromagnetic phase in the system at 0.5 < x < 0.15. The spin state of Co ions is not affected by the Ti doping and remains an intermediate-spin state at x < 0.15. At low temperatures, the system is in a reentrant spin glass state. Phase separation provides a phenomenological interpretation of these magnetic behaviors. A detailed phase diagram of La_(0.5)Ba_(0.5)Co_(1-X)Ti_xO_3 has been constructed.