| The internal magnetic field distributions for a type II superconductor (a single crystal YBa2Cu3O7-delta ) with large normal inclusions (YBa2Cu3O 7-delta) are studied. A model based on the London Equations has been successfully developed and applied to the interpretation of the pSR data on this system. In our model, these inclusions are assumed to be cylindrical in shape and infinite in length. Therefore, this model should be especially appropriate for the prediction of field distributions in single crystal superconductors in which columnar defects have been purposely introduced to enhance pinning.; muSR experiments on a large single-crystal sample of YBa2C u3O7-delta with non-conducting YBa2Cu3 O7-delta inclusions show some interesting characteristics, especially the magnetic field distribution in the inclusion regions. In our model, the difference between the field value in the inclusions and the value at the saddle point is sensitive to the penetration depth. Comparing the calculated to observed field differences provides a new method for determining the penetration depth. |
