(a) Experimental configuration during the measurements: the current was injected in samples S1 and S2 (same width ) through large copper electrodes pressed against the top metallic shunt (substrate on the bottom side), and the voltage was measured over a distance ; (b) structure of the two CC samples considered in this paper.
Example of PCM on a CC. The dashed line shows the current intensity and the full line the mean measured electric field as functions of time. The electric field “at zero temperature rise” is obtained by extrapolating the electric field slope back to the point where the current waveform has reached 90% of its final value, as shown by the dotted lines.
Experimental current-voltage characteristics of samples S1 and S2 at 77 K (symbols) and voltages calculated in the flux flow and Ohmic regimes (full lines); is the samples critical current, is the current extrapolated to zero voltage of the flux flow characteristics, and is the current at the transition between the two linear regimes. The insets show the same characteristics on a semilog scale.
Electrical circuit equivalent to the system consisting of the superconducting and the metallic layer(s) in the flux flow regime.
Current (a) flowing in the superconducting film of samples S1 and S2 and vortex velocity (b) in the flux flow and the Ohmic regimes, as a function of the total current flowing in the samples.
Flux flow critical current, , i.e., current extrapolated to zero voltage in the flux flow regime (regime L1) and current at the transition between the linear regimes L1 and L2, of samples S1 and S2; is the global resistance of the metallic layers of the CCs at the measurement temperature (77 K), and and are the dynamic resistances measured in regimes L1 and L2, respectively.
Calculated vortex velocity , measured and calculated dynamic resistance, , for samples S1 and S2 in the flux flow regime (L1). is the power dissipated for . The values in parentheses are calculated using Eq. (5) to determine .
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