Zr50Sc12O43N50 and Zr3Sc4N8 - Synthesis, neutron powder diffraction and Raman spectroscopy
Zeitschrift Fur Anorganische Und Allgemeine Chemie 633(5-6): 790-794
The nitridation of Zr50Sc12O118 (Zr0.807Sc0.193O1.90), an anion deficient fluorite related compound, with ammonia yields at 1100 degrees C a green product with composition Zr1.613Sc0.387O1.387N1.613. This compound crystallizes cubic in space group Ia (3) over bar (a = 1007.8(5) pm) and is isostructural to Bixbyite with statistical distribution of Zr/Sc at the cation and of O/N at the anion sites. These are the results of Rietveld refinements from a powder neutron diffraction experiment. If Zr3Sc4O12 (Zr0.429Sc0.571O1.714), an educt with another Zr/Sc ratio, is nitridated with ammonia the reaction path shows again the formation of a compound with a bixbyite structure, but finally at 1200 degrees C a red nitride with the composition Zr3Sc4N8 (Zr0.375Sc0.5N) is formed. This compound has a cation deficient NaCl type structure (space group is Fm (3) over barm) with a = 452.8(1) pm. Neutron diffraction revealed again no ordering on the cation sites. Both compounds show an unperturbed N N stretching frequency in their Raman spectrum at 2327 cm(-1). Zr3Sc4N8 exhibits at 1552 cm(-1) a second sharp line which was assigned to a N-2(2-) moiety.