Citrate-nitrate combustion route to the synthesis of (1-x)LaCrO ₃-xBiCrO₃ solid solution

Solid solution of (1-x)LaCrO₃-xBiCrO₃ (x=0, 0.10, 0.15, 0.20 and 0.25) was prepared via the citrate-nitrate combustion synthesis. Pure perovskite phase was obtained at 800°C, a much lower synthesis temperature than that needed in the solid-state reactions. The thermodynamics of phase formation and the ceramic sintering mechanism were investigated. The substitution of Bi³⁺ for La³⁺ was found to give a separate exothermic decomposition event in the gels and the precursor did not produce a transient liquid phase while heating to 1200°C, as was found in ceramics prepared by solid state reaction. This finding shows that the role of Bi ₂O₃ in the sintering of the La_1-x Bi _x CrO₃ ceramics depends on the processing method.