Dependence of critical current densities in Chevrel phase superconducting wires on magnetic fields up to 25 T
Résumé
V-I characteristics have been measured, in several monofilamenry Chevrel phase superconductors (CPS) wires made using prereacted powders of both pure SnMo₆S₈ (SMS) and Pb₀ꓸ₆Sn₀ꓸ₄Mo₆ؘؘS₈ (PSMS) compounds, in applied magnetic fields up to 25T. The values of Jc in different wires lie in the range ∼ 5 × 10⁷ −10⁹ A/m2 at 4.2 K and 9T. In the SMS wires the critical current density Jc(B) tends to vanish at the expected ideal Bc2. In contrast, for PSMS wires the Jc(B) tends to vanish at fields much smaller than the expected Bc₂ for pure PbMo₆S₈ (PMS) and nearer to that of SMS. The V-I characteristics at the dissipative onset are highly non-linear and show a power law behaviour V = kIⁿ with a typical n-value (1.8K, 26T) > 17.
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