Antiferromagnetism Brownmillerites Charge transfer Charge transfer energy Degrees of freedom (mechanics) Doping (additives) Electron-phonon interactions Energy gap Ferromagnetic materials Ferromagnetism Filling Gap opening Insulation Iron compounds Lanthanum compounds Ligands Metal insulator boundaries Metal insulator transition Metal-to-insulator transitions Metallic phase Metals N-Doping N-doped Negative charge Nickel compounds Oxygen Passivation Perovskite Spin degrees of freedom Spin lattices