Synthesis and crystal structure of rutile-type ScTa₂O₅N

A new phase in the system Sc-Ta-O-N was synthesized by reaction of an amorphous oxide precursor with a gaseous NH₃/O₂ mixture at 800 C. Crystal structure determination was performed using X-ray powder data. ScTa₂O₅N crystallizes in the tetragonal space group P4₂/mnm (rutile-type structure) and exhibits a brilliant yellow color (optical bandgap: 2.67 eV), making it a promising material for photocatalytical water splitting. Further investigation methods (SEM, TEM, and N₂-physisorption) were applied for more detailed characterization of the new phase. Unfortunately, the new compound could not be prepared as pure phase. So far a phase purity of ca. 90 % was the best result. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)