Reversible magnetization of a thin superconducting film with radiation defects

The thermodynamic potential of a system of Peierls vortices in a thin super conducting film, containing radiation defects, in a perpendicular external magnetic field is calculated. The equilibrium temperature dependences of th e densities of free vortices and vortices trapped by defects are found in t he mean-field approximation for various magnitudes of the external field. I t is shown that the equilibrium magnetization of a thin superconducting fil m exhibits the same features that were observed experimentally in the rever sible magnetization of high-temperature superconductors. An asymptotic expr ession is obtained for the difference of the magnetizations of perfect and irradiated films. According to this expression, the difference depends on t he pinning energy of a vortex on a defect and the density of defects. (C) 2 000 MAIK "Nauka/Interperiodica".