Observation of Persistent Currents in Finely Dispersed Pyrolytic Graphite

• Published in: JETP letters Vol. 107; no. 1; pp. 37 - 41
• Main Authors: Saad, M., Gilmutdinov, I. F., Kiiamov, A. G., Tayurskii, D. A., Nikitin, S. I., Yusupov, R. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 2018; Springer Nature B.V
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Condensed Matter; Graphite; Magnetic fields; Magnetic flux; Magnetism; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Pyrolytic graphite; Quantum Information Technology; Solid State Physics; Spintronics; Superconductivity
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364018010101

The trapped magnetic flux in the finely ground pyrolytic graphite sample annealed at 670 K in air has been observed. Flux trapping occurs on cooling of the sample from room temperature to 10 K in a magnetic field of 1 T. The magnitude and sign of the induced trapped moment remain unchanged when the applied magnetic field is varied within ±1 T at T K. The trapped magnetic flux is manifested in the displacement of the magnetization curve relative to that of the sample cooled in zero field. Displacement magnitude gradually decreases with the temperature increase up to 350 K, not reaching zero. The set of experimental observations probably reflects the presence in the sample of a granular high-temperature superconducting phase.