2005

EquilibriaE 4000 Prediction of Novel Phases of Tantalum(V) Nitride and Tungsten(VI) Nitride that

Can Be Synthesized under High Pressure and High Temperature. — Based on a combination of quantum chemical and thermochemical calculations the existence of the novel modifications Ta3N5-II, WN2-I, and WN2-II, which should be accessible by chemical synthesis at high pressures, is predicted. The Cmcm modification Ta3N5-I will undergo a structural transition to Ta3N5-II at 9 GPa. Using N2 as both pressure medium and reactant Ta3N5-II can be synthesized from the mononitride at pressures above 17 or 25 GPa at 2800 K. WN2-II becomes accessible above 31 or 55 GPa at this temperature. — (KROLL*, P.; SCHROETER, T.; PETERS, M.; Angew. Chem., Int. Ed. 44 (2005) 27, 4249-4254; Inst. Anorg. Chem., RWTH Aachen, D-52074 Aachen, Germany; Eng.) — W. Pewestorf

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