Magnetization measurement of a possible high-temperature superconducting state in amorphous carbon doped with sulfur

2009/02/26 by I. Felner, Israel Felner, Y. Kopelevich +1
Chemistry · Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Amorphous solid #Chemistry #Condensed matter physics #Critical field #Crystallography #Diamond and Carbon-based Materials Research #Doping #Ferromagnetism #Graphene research and applications #High-pressure geophysics and materials #Magnetic field #Magnetization #Materials science #Phase (matter) #Phase boundary #Phase diagram #Physics #Superconductivity #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.79.233409

18 pages including 5 figures

arxiv created 2009/02/26 · openalex publication_date 2009/06/30 · arxiv updated 2015/05/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Magnetization M(T,H) measurements performed on thoroughly characterized commercial amorphous carbon powder doped with sulfur (AC-S), revealed the occurrence of an inhomogeneous superconductivity (SC) below T_c=38 K. The constructed magnetic field-temperature (H\text\ensuremath-T) phase diagram resembles that of type-II superconductors. However, AC-S demonstrates a number of anomalies, such as: (1) a nonmonotonic behavior of the lower critical-field H_c1(T); (2) a pronounced positive curvature of the apparent upper critical-field boundary H_c2(T); and (3) a spontaneous ferromagneticlike magnetization M₀ coexisting with SC. Based on the analysis of experimental results we propose a nonstandard SC state in AC-S.

Citations

• Superconductivity of BulkCaC6
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• Low-Energy Electrodynamics of Superconducting Diamond
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• The electronic properties of graphene
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