Charge-Orbital Ordering in Ferromagnetic and Charge-Exchange-Type Antiferromagnetic Phases for Half-Doped Manganites

Using a two-orbital DE model including the Coulomb interaction, we show that the charge-orbital ordering usually found in the charge-exchange phase may exist in the ferromagnetic phase for half-doped manganites. Thus, two types of phase transitions observed experimentally can be explained by the obtained phase diagram.