Suppression of Magnetic Relaxation in a High-Temperature Superconductor Placed near a Ferromagnet

The phenomenon of the suppression of magnetic relaxation in a high-temperature superconductor (HTSC) with trapped magnetic flux has been observed when the superconducting sample approached a ferromagnet. It is suggested that the ferromagnet is magnetized in the magnetic field of the sample and, in turn, induces currents in the superconductor, which circulate in a direction opposite to that of the trapped flux current. As a result, the magnetic structure becomes stable with respect to the magnetic flux creep because oppositely directed Lorentz forces can act upon different regions of vortices.