Agenda

Prochain séminaire LANEF/Matériaux Quantiques :

Jeudi 13 février 2025 à 14h00

Manuel Núñez-Regueiro (Institut Néel)

“ Magnetic field sorting of superconducting graphite particles with Tc > 400K “

Pour accéder à ce séminaire :

Institut Néel CNRS, Bâtiment K, Salle Rémy Lemaire  (K223)

Résumé : It has been claimed that graphite hosts superconductivity at room temperature, although all efforts to isolate it have been vain.  Here we report separation methods that use magnetic field gradients to sort the superconducting from  normal grains out of industrial graphite powders. We have obtained a concentrate of above room temperature superconducting particles. Electrical resistance measurements on agglomerates of sorted grains of synthetic, natural and spectroscopically pure graphite all show transition temperatures up to Tc^{^{onset}}~700 K with  zero resistance up to ~500K. Magnetization measurements confirm these values through jumps  at Tc in the zero field cooled curves, and by the occurrence of diamagnetic hysteretic cycles  shrinking with temperature. Transmission electron microscope images yield a hint of the novel structure of these grains.

Les organisatrices :

Elsa Lhotel (elsa.lhotel@neel.cnrs.fr)
Florence Levy-Bertrand (florence.levy-bertrand@neel.cnrs.fr)