Ferromagnetic half-metallicity in YBaCo2O6 and spin-state driven metal–insulator transition

Cobaltates have rich spin-states and diverse properties. Using spin-state pictures firstprinciples calculations, here we study the electronic structure magnetism of mixed-valent double perovskite YBaCo2O6. We find that YBaCo2O6 is in formal intermediate-spin (IS) Co3+/low-spin (LS) Co4+ ground state. The hopping eg electron from IS-Co3+ to LS-Co4+ via exchange gives rise a ferromagnetic half-metallicity, which well accounts for recent experiments. reduction both magnetization Curie temperature by oxygen vacancies discussed, aided with Monte Carlo simulations. also explore several other possible their interesting electronic/magnetic Moreover, predict volume expansion more than 3% would tune into high-spin (HS) Co3+/LS state simultaneously drive metal-insulator transition. Therefore, are useful parameter tuning material properties cobaltates.