title: Novel superconducting skutterudite-type phosphorus nitride at high pressure from first-principles calculations.
abstract: State of the art variable composition structure prediction based on density functional theory demonstrates that two new stoichiometries of PN, PN3 and PN2, become viable at high pressure. PN3 has a skutterudite-like Immm structure and is metastable with positive phonon frequencies at pressures between 10 and 100 GPa. PN3 is metallic and is the first reported nitrogen-based skutterudite. Its metallicity arises from nitrogen p-states which delocalise across N4 rings characteristic of skutterudites, and it becomes a good electron-phonon superconductor at 10 GPa, with a Tc of around 18 K. The superconductivity arises from strongly enhanced electron-phonon coupling at lower pressures, originating primarily from soft collective P-N phonon modes. The PN2 phase is an insulator with P2/m symmetry and is stable at pressures in excess of 200 GPa.
authors: 1] Sorbonne Universités, UPMC Univ. Paris 06, UMR 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France [2] CNRS, UMR 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France.
authors: Zamaan
authors: Z
authors: Raza
authors: 1] Sorbonne Universités, UPMC Univ. Paris 06, UMR 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France [2] Donostia International Physics Center (DIPC), Manuel de Lardizabal pasealekua 4, 20018 Donostia-San Sebastián, Basque Country, Spain [3] IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
authors: Ion
authors: I
authors: Errea
authors: 1] Department of Geosciences, State University of New York, Stony Brook, NY 11794-2100, USA [2] Center for Materials Design, Institute for Advanced Computational Science, State University of New York, Stony Brook, NY 11794-2011, USA [3] Moscow Institute of Physics and Technology, 9 Institutskiy Lane, Dolgoprudny City, Moscow Region, 141700, Russian Federation [4] Northwestern Polytechnical University, Xi'an, 710072, China.
authors: Artem R
authors: AR
authors: Oganov
authors: 1] Sorbonne Universités, UPMC Univ. Paris 06, UMR 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France [2] CNRS, UMR 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France.
authors: A Marco
authors: AM
authors: Saitta