Relaxation of the magnetization in the pinning state of high-Tc superconductors

As one of the bases of the theoretical estimation of the electromagnetic properties for practical purposes in wires, conductors and coils using high-Tc cuprate superconductors, the expression for the time decay of the magnetization in a slab sample of the high-Tc cuprate superconductor is derived by solving the Maxwell equations with the aid of the expression for the electric field, E, vs. current density, J, characteristic that was derived recently by the authors. The obtained expression, which is noticeably different from the one for the low-Tc metallic superconductors, is compared quantitatively with the numerical calculations, and the agreement between them seems to be satisfactory.