Preparation and optical properties of Bi₂O₃ doped Sm_0.5Sr_0.5CoO_3-δ

Perovskite-type oxides (Sm_1-xBi_x)_0.5Sr_0.5CoO_3-δ0 (0 ≤x≤ 0.5) were successfully prepared by a solid-state reaction method. The effect of Bi³⁺ doping concentration on the crystal structure, microstructure, solar absorbance and thermal emittance properties of (Sm_1-xBi_x)_0.5Sr_0.5CoO_3-δ was investigated. Results indicate that the single orthorhombic perovskite structure was obtained for 0≤x≤0.2; when 0.3≤x≤0.5, the main phase was the perovskite orthorhombic structure while a small amount of inpurity phases CoO and Sr_0.5CoBi_0.5O_x emerged. The average particle size of SBSC was increased from 1.98 μm to 9.77 μm as the Bi³⁺ concentration increasing, and the grain morphology changed from polygon to bulk as result of Bi³⁺ doping. The incorporation of Bi³⁺ doped into Sm³⁺ sites were found to enhance the solar absorbance from 0.73 to 0.87 and to stimultaneously increase the infrared emittance from 0.34 to 0.80.