We report the discovery of superconductivity in a new family of orthorhombic Tantalum nitride synthesised under high pressure and stable after pressure releasing, with a superconducting transition temperature T$_c$ of 3K at ambient pressure, that reaches 9~K at 18~GPa. This compound exhibits a unique combination of structural and electronic properties, with a very high hardness combined with a significant ductility and high fracture toughness together with a superconducting phase. Interesingly, low oxygen content has been detected with a large effect on the T$_c$. This potential doping effect together with potential superconducting coupling via light element nitrogen ions phonons and strong covalent bonds makes this new family promising for the search of high-T$_c$ light-element-based superconductors.
|Choix de session parallèle||1.2 La supraconductivité par couplage électron-phonon dans les composé à éléments légers: vers la température ambiante?|