Local Study of Magnetic Structures in High-Temperature Superconducting Composites

The results of magneto-optical investigations of the magnetization processes in high-temperature superconducting coated conductor composites are presented. The studies were performed in the temperature range of 4–80 K. It is shown that the re-magnetization of composites in external magnetic field is accompanied by formation and propagation of the magnetic flux annihilation waves (areas with zero magnetic induction). The relationship between penetration depth of annihilation front and the value of external magnetic field at different temperatures as well as temperature dependence of the rate of magnetic flux annihilation front motion are found. The experimental data agree qualitatively with the results of numerical calculations performed by using the Monte Carlo method.