Effect of Sample Thickness on Magneto-Optic Imaging for Vortex Fully Penetrated Square-Shaped Superconductors

A significant effect of sample thickness on three components of the magnetic flux density distribution on square-shaped superconductor surface is shown, and the critical current density j_c of the superconductor from the fully penetrated field μ₀H^* observed in magneto-optic imaging experiment is calculated.