Magnetic shielding effect on oxide superconducting plates

The authors have measured a critical shielding flux density B ₀₁ of YBa₂Cu₃O_y superconducting plates. Sintered specimens were assumed to be bulk superconductors with interconnected sub-structures and were considered to screen the magnetic field completely for applied fields of less than B₀₁. The critical shielding flux density was proportional to the thickness d of the specimen, as expected from an equation derived from the Bean-London critical state model. The authors have obtained 16 G/mm as a maximum shielding capacity of B ₀₁/d. The measured flux showed hysteresis when the applied field was raised above B₀₁/