Examinando por Autor "Voigt, Laura"

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    Ítem
    Formation of the layered conductive magnet CrCl2(pyrazine)2 through redox-active coordination chemistry
    (Nature Publishing Group, 2018-10) Pedersen, Kasper S.; Perlepe, Panagiota; Aubrey, Michael; Woodruff, Daniel N.; Reyes-Lillo, Sebastian E.; Reinholdt, Anders; Voigt, Laura; Li, Zheshen; Borup, Kasper; Rouzières, Mathieu; Samohvalov, Dumitru; Wilhelm, Fabrice; Rogalev, Andrei; Neaton, Jeffrey B.; Long, Jeffrey R.; Clérac, Rodolphe
    The unique properties of graphene, transition-metal dichalcogenides and other two-dimensional (2D) materials have boosted interest in layered coordination solids. In particular, 2D materials that behave as both conductors and magnets could find applications in quantum magnetoelectronics and spintronics. Here, we report the synthesis of CrCl2(pyrazine)2, an air-stable layered solid, by reaction of CrCl2 with pyrazine (pyz). This compound displays a ferrimagnetic order below ∼55 K, reflecting the presence of strong magnetic interactions. Electrical conductivity measurements demonstrate that CrCl2(pyz)2 reaches a conductivity of 32 mS cm–1 at room temperature, which operates through a 2D hopping-based transport mechanism. These properties are induced by the redox-activity of the pyrazine ligand, which leads to a smearing of the Cr 3d and pyrazine π states. We suggest that the combination of redox-active ligands and reducing paramagnetic metal ions represents a general approach towards tuneable 2D materials that consist of charge-neutral layers and exhibit both long-range magnetic order and high electronic conductivity. © 2018, The Author(s).
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    Ítem
    From an antiferromagnetic insulator to a strongly correlated metal in square-lattice MCl2(pyrazine)2 coordination solids
    (Nature Research, 2022-12) Perlepe, Panagiota; Oyarzabal, Itziar; Voigt, Laura; Kubus, Mariusz; Woodruff, Daniel N.; Reyes-Lillo, Sebastian E.; Aubrey, Michael L.; Négrier, Philippe; Rouzières, Mathieu; Wilhelm, Fabrice; Rogalev, Andrei; Neaton, Jeffrey B.; Long, Jeffrey R.; Mathonière, Corine; Vignolle, Baptiste; Pedersen, Kasper S.; Clérac, Rodolphe
    Electronic synergy between metal ions and organic linkers is a key to engineering molecule-based materials with a high electrical conductivity and, ultimately, metallicity. To enhance conductivity in metal-organic solids, chemists aim to bring the electrochemical potentials of the constituent metal ions and bridging organic ligands closer in a quest to obtain metal-d and ligand-π admixed frontier bands. Herein, we demonstrate the critical role of the metal ion in tuning the electronic ground state of such materials. While VCl2(pyrazine)2 is an electrical insulator, TiCl2(pyrazine)2 displays the highest room-temperature electronic conductivity (5.3 S cm–1) for any metal-organic solid involving octahedrally coordinated metal ions. Notably, TiCl2(pyrazine)2 exhibits Pauli paramagnetism consistent with the specific heat, supporting the existence of a Fermi liquid state (i.e., a correlated metal). This result widens perspectives for designing molecule-based systems with strong metal-ligand covalency and electronic correlations. © 2022, The Author(s).
  • No hay miniatura disponible
    Ítem
    From an antiferromagnetic insulator to a strongly correlated metal in square-lattice MCl2(pyrazine)2 coordination solids
    (Nature Research, 2022-12) Perlepe, Panagiota; Oyarzabal, Itziar; Voigt, Laura; Kubus, Mariusz; Woodruff, Daniel N.; Reyes Lillo, Sebastian E.; Aubrey, Michael L.; Négrier, Philippe; Rouzières, Mathieu; Wilhelm, Fabrice; Rogalev, Andrei; Neaton, Jeffrey B.; Long, Jeffrey R.; Mathonière, Corine; Vignolle, Baptiste; Pedersen, Kasper S.; Clérac, Rodolphe
    Electronic synergy between metal ions and organic linkers is a key to engineering molecule-based materials with a high electrical conductivity and, ultimately, metallicity. To enhance conductivity in metal-organic solids, chemists aim to bring the electrochemical potentials of the constituent metal ions and bridging organic ligands closer in a quest to obtain metal-d and ligand-π admixed frontier bands. Herein, we demonstrate the critical role of the metal ion in tuning the electronic ground state of such materials. While VCl2(pyrazine)2 is an electrical insulator, TiCl2(pyrazine)2 displays the highest room-temperature electronic conductivity (5.3 S cm–1) for any metal-organic solid involving octahedrally coordinated metal ions. Notably, TiCl2(pyrazine)2 exhibits Pauli paramagnetism consistent with the specific heat, supporting the existence of a Fermi liquid state (i.e., a correlated metal). This result widens perspectives for designing molecule-based systems with strong metal-ligand covalency and electronic correlations. © 2022, The Author(s).