Critical current and magnetic flux noise of YBaCuO thin films in the presence of flux creep

The pinning potential U of YBaCuO films in weak magnetic fields is studied experimentally. It is shown that the pinning potential increases with the increase in the critical current density J_c; values of U(T=0)=25-120 meV are obtained for the films with J_c(T=0)=5.3×10⁵-1.8×10⁷ A/cm². The temperature dependence of the pinning potential U(T) is also obtained. The experimental results can be explained qualitatively by the pinning model of isolated vortices. The properties of the 1/f flux noise of the film are also discussed with the experimental results of the pinning potential. It is shown that the dependences of the flux noise on the temperature and the critical current density can be explained by the properties of the pinning potential