High temperature magnetic and transport properties of PrBaCo2O6– δ cobaltite: Spin blockade evidence

The experimental data are presented for magnetic susceptibility and electrical conductivity in PrBaCo₂O_6–δ at 850–1223 K. The decrease of oxygen content at heating is accompanied by formation of Co³⁺ cations that may simultaneously reside in oxygen pyramidal and octahedral coordination with intermediate and high spins, respectively. The small polaron p-type electron transport is shown to be mediated by the intermediate-spin Co³⁺ while high-spin Co³⁺ cations in octahedral environment are excluded from polaron jumps due to the spin blockade effect.