Affiliation:
1. Department of Chemistry University of Munich (LMU) Butenandtstraße 5–13 81377 Munich Germany
2. Department of Physics and Engineering Physics University of Saskatchewan 116 Science Place Saskatoon, Saskatchewan S7N 5E2 Canada
3. Institute for Inorganic Chemistry and Crystallography Leipzig University Scharnhorststraße 20 04275 Leipzig Germany
Abstract
AbstractWe report on the synthesis, crystal, and electronic structure, as well as the magnetic, and electric properties of the phosphorus‐containing tantalum nitride P1−xTa8+xN13 (x=0.1–0.15). A high‐pressure high‐temperature reaction (8 GPa, 1400 °C) of Ta3N5 and P3N5 with NH4F as a mineralizing agent yields the compound in the form of black, rod‐shaped crystals. Single‐crystal X‐ray structure elucidation (space group C2/m (no. 12), a=16.202(3), b=2.9155(4), c=11.089(2) Å, β=126.698(7)°, Z=2) shows a network of face‐ and edge‐sharing Ta‐centered polyhedra that contains small vacant channels and PN6 octahedra strands. Atomic resolution transmission electron microscopy reveals an unusual P/Ta disorder. Mixed‐valent tantalum atoms exhibit interatomic distances similar to those in metallic tantalum, however, the electrical resistivity is quite high in the order of 101 Ω cm. The density of states and the electron localization function indicate localized electrons in both covalent and ionic bonds between P/Ta and N atoms, combined with less localized electrons that do not contribute to interatomic bonds.