The relaxation of magnetization M in superconducting C60Rb3 have been measured at different temperature ranges in low magnetic fields below Tc to explore the flux pinning. The measurements were performed with a superconducting quantum interference magnetometer. The applied magnetic field was 300 G - 600 G and the measured time at each temperature was 1 × 104 sec. M versus 1nt shows a linear behavior for t ≥ 3600 sec. The data were analyzed in the framework of the flux pinning model of Anderson-Kim. The analyses give the activation energy of U(5K) ≈ 20 mev, and the critical current density based on Jc(T) ∝ [dM/dlnt] × [U/kT] shows Jc ∝ (1-t)m, with the exponent m ≈ 2.0. The results are discussed.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering