Meissner - London state in superconductors of rectangular cross-section   in perpendicular magnetic field
  The distribution of magnetic induction in Meissner state with finite London penetration depth is analyzed for platelet samples of rectangular cross-section in a perpendicular magnetic field. The exact 2D numerical solution of the London equation is extended analytically to the realistic 3D case. Data obtained on Nb cylinders and foils as well as single crystals of YBCO and BSCCO are in a good agreement with the model. The results are particularly relevant for magnetic susceptibility, rf and microwave resonator measurements of the magnetic penetration depth in high-Tc superconductors. 
R. Prozorov, R. W. Giannetta, A. Carrington, F. M. Araujo-Moreira