Effects of Vortex Pinning on the Temperature Dependence of the Magnetic Field Distributions in Superconductors

The temperature and applied-magnetic-field dependence of the second moments of the magnetic-field distributions as measured by μSR for YBCO and BSCCO have been fit for four different intrinsic-field-distribution models (d-wave, 2-fluid, empirical, and BCS). It is found that if a pinning potential becomes important at about 20 K, all of the models can fit the data reasonably well. The fits and the associated fitting parameters are presented.