Interaction between superconducting and ferromagnetic order parameters in graphite-sulfur composites

The superconductivity of graphite-sulfur composites is highly anisotropic and associated with the graphite planes. The superconducting state coexists with the ferromagnetism of pure graphite, and a continuous crossover from superconducting to ferromagneticlike behavior could be achieved by increasing the magnetic field or the temperature. The angular dependence of the magnetic moment $m(\ensuremath{\alpha})$ provides evidence for an interaction between the ferromagnetic and the superconducting order parameters.