Magnetic levitation force between a superconducting bulk magnet and a permanent magnet

The current density J(ρ, z) in a disc-shaped superconducting bulk magnet and the magnetic levitation force FSBMz exerted on the superconducting bulk magnet by a cylindrical permanent magnet are calculated from first principles. The effect of the superconducting parameters of the superconducting bulk is taken into account by assuming the voltage–current law E = Ec(J/Jc)n and the material law B = μ0H. The magnetic levitation force FSBMz is dominated by the remnant current density J'2(ρ, z), which is induced by switching off the applied magnetizing field. High critical current density and flux creep exponent may increase the magnetic levitation force FSBMz. Large volume and high aspect ratio of the superconducting bulk can further enhance the magnetic levitation force FSBMz.