Determination of pinning energy U0 for melt textured YBCO in accord with collective pinning theory

In collective pinning theory, vortex pinning energy, U, is a key parameter in describing thermally activated flux motion, but it is a function of the critical current density Jc, glassy exponent μ and pinning energy U0, under the base of Griessen's and our group's methods of obtaining Jc and μ, respectively. Determining U0 is a troublesome problem. In this paper, we introduce a new way of determining pinning energy U0, thus, the complex problem of getting U has been solved successfully.