The effect of reducing environments on the stability of acceptor substituted yttrium chromite

摘要: Abstract The dimensional stability of calcium-substituted yttrium chromite was evaluated over a wide range temperatures, oxygen partial pressures, and compositions, compared to data collected for calcium-doped lanthanum chromite. Sample expansion dependent on the concentrations acceptor dopant CaCrO4, secondary phase observed in samples with greater than 25 mole% calcium, as well measurement temperature pressure. instability reducing environments directly related loss lattice simultaneous reduction Cr4+ Cr1+ maintain electroneutrality. evolution chromium resulted expansion, caused by size change associated Cr3+ transition electrostatic repulsion between adjacent octahedra. measured chromites 42% less that similarly doped chromites. is result decreased unit cell (6.5% smaller chromite) which suppresses hindering during reduction.