- AutorIn
- Christian E. Precker
- Pablo D. Esquinazi
- Ana Champi
- José Barzola-Quiquia
- Mahsa Zoraghi
- Santiago Muinos-Landin
- Annette Setzer
- Winfried Böhlmann
- Daniel Spemann
- Jan Meijer
- Tom Münster
- Oliver Bähre
- Gert Klöss
- Henning Beth
- Titel
- Identification of a possible superconducting transition above room temperature in natural graphite crystals
- Zitierfähige Url:
- https://nbn-resolving.org/urn:nbn:de:bsz:15-qucosa-216014
- Quellenangabe
- New J. Phys. 18 (2016) 113041 doi:10.1088/1367-2630/18/11/113041
- Erstveröffentlichung
- 2016
- Abstract (EN)
- Measuring with high precision the electrical resistance of highly ordered natural graphite samples from a Brazil mine, we have identified a transition at ∼350 K with ∼40 K transition width. The steplike change in temperature of the resistance, its magnetic irreversibility and time dependence after a field change, consistent with trapped flux and flux creep, and the partial magnetic flux expulsion obtained by magnetization measurements, suggest the existence of granular superconductivity below 350 K. The zero-field virgin state can only be reached again after zero field cooling the sample from above the transition. Paradoxically, the extraordinarily high transition temperature we found for this and several other graphite samples is the reason why this transition remained undetected so far. The existence of well ordered rhombohedral graphite phase in all measured samples has been proved by x-rays diffraction measurements, suggesting its interfaces with the Bernal phase as a possible origin for the high-temperature superconductivity, as theoretical studies predicted. The localization of the granular superconductivity at these two dimensional interfaces prevents the observation of a zero resistance state or of a full Meissner state.
- Andere Ausgabe
- Link zur Originalpublikation in der Zeitschrift New Journal of Physics
Link: http://dx.doi.org/10.1088/1367-2630/18/11/113041 - Freie Schlagwörter (DE)
- Graphit, Supraleitung
- Freie Schlagwörter (EN)
- graphite crystal, superconductivity
- Klassifikation (DDC)
- 530
- Herausgeber (Institution)
- Universität Leipzig
- Universidade Federal do ABC
- Golden Powerbird Pty Ltd.
- IOP Publishing
- URN Qucosa
- urn:nbn:de:bsz:15-qucosa-216014
- Veröffentlichungsdatum Qucosa
- 12.12.2016
- Dokumenttyp
- Artikel
- Sprache des Dokumentes
- Englisch