P1−xTa8+xN13 (x=0.1–0.15): A Phosphorus Tantalum Nitride Featuring Mixed‐Valent Tantalum and P/Ta Disorder Visualized by Scanning Transmission Electron Microscopy

Pointner, Monika M. ; Ceniza, Claude ; Nusser, Lukas; Witthaut, Kristian ; Wolf, Florian ; Weidemann, Martin ; Eisenburger, Lucien ; Moewes, Alexander ; Oeckler, Oliver und Schnick, Wolfgang (2024): P1−xTa8+xN13 (x=0.1–0.15): A Phosphorus Tantalum Nitride Featuring Mixed‐Valent Tantalum and P/Ta Disorder Visualized by Scanning Transmission Electron Microscopy. In: Angewandte Chemie International Edition, Bd. 63, Nr. 45

Abstract

We 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.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 1433-7851
• Sprache: Englisch
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390776260