KCS

Oxynitride type complex perovskites AM0.2Ta0.8O3-XNX (A = Sr, Ba; M = Li, Na, Mg, Ca) were newly synthesized by the solid state reaction between XCO3(X = Li, Na), X’ Cl2(X’ = Mg, Ca) and A5Ta4O15 in the ammonia atmosphere. The formation of ACa0.2Ta0.8O2.6N0.4 prepared by an intercalation-type synthetic approach using the layered perovskite A5Ta4O15, Alkali insertion is enabled by charge compensation from aliovalent O/N substitution. Rietveld refinement of the X-ray diffraction patterns indicated that BaM0.2Ta0.8O3-XNX (M = Li, Na, Mg, Ca) is simple cubic (Pm3 ̅m) and SrM’0.2Ta0.8O3-XNX ( M’ = Li, Na, Mg) is body-centered tetragonal (I4Imcm), exceptively When the alkali cations inserted the SrM0.2Ta0.8O3-X, they formed a tetragonal structure, but when Ca was inserted, they formed a cubic structure. The group of simple and complex perovskites, ATaO2N, ALi0.2Ta0.8O2.8N0.2, ANa0.2Ta0.8O2.8N0.2, AMg0.2Ta0.8O2.6N0.4, and ACa0.2Ta0.8O2.6N0.4 (A = Sr, Ba) covers the band gap range, 1.8-2.4 eV, and the color ranges from yellow to dark brown.