Zur Struktur der Selenide Cs₂Pd₃Se₄, Rb₂Pd₃Se₄ und K₂Pd₃Se₄ / On the Crystal Structure of Cs₂Pd₃Se₄, Rb₂Pd₃Se₄, and K₂Pd₃Se₄

Abstract

The ternary selenides Cs 2 Pd 3 Se 4 , Rb 2 Pd 3 Se 4 and K 2 Pd 3 Se 4 have been prepared by fusion reactions of alkali carbonates with palladium and selenium at 850°C. According to X-ray powder patterns (Guinier-Simon technique) Cs 2 Pd 3 Se 4 is monoclinic with α= 6,49 3 Å, b =14,20 4 Å, c = 6,41 4 Å, β=120,41 ° and is isotypic with Cs 2 Pd 3 S 4 (C 2/m, No. 12). Rb 2 Pd 3 Se 4 and K 2 Pd 3 Se 4 are orthorhombic and isotypic with K 2 Pd 3 S 4 (Fddd, No. 70). Rb 2 Pd 3 Se 4 : α=11,07 6 Å, b = 27,09 2 Å, c= 6,35 3 Å; K 2 Pd 3 Se 4 : a= 10,95 4 Å, b = 26,19 6 A, c = 6,31 7 Å.