Synthesis and Crystal Structure of the First Sc-Nb-O-N Phases

Synthesis of phase-pure materials in the system Sc-Nb-O-N is challenging. In this contribution we report on the preparation of the first scandium niobium oxide nitrides via reaction of water-saturated gaseous ammonia or an ammonia-oxygen mixture with amorphous scandium niobium oxides. Two new phases were obtained: rutile-type ScNb4O7N3, which crystallizes in space group P42/mnm, and an anion-deficient fluorite-type Sc2Nb(O,N,⬜)6 phase crystallizing in space group Fm3m.