Scaling of flux pinning with the thermodynamic critical field

A systematic study of flux pinning and the thermodynamic critical field H-c has been undertaken to determine whether H-c is a central factor determini ng the critical current J(c),. Materials that have a fairly wide temperatur e interval of thermodynamic reversibility are selected so that the thermody namic critical field can be confidently extrapolated into the irreversible regime. J(c) is found to scale with H-c. For a given sample, the J(c)/H-c v s H/H-c curves are close to a universal function as temperature changes. In addition, the peak in the pinning force curve also scales with H-c(2) for a wide variety of samples having quite different transition temperatures. [ S0163-1829(99)15029-X].