Local magnetooptical study of magnetic structures in high-temperature superconducting composites

The results from magnetooptical investigations of the remagnitization processes in composite film structures based on high-temperature superconductors in the temperature range of 4 to 80 K are presented. It is shown that the remagnetization of structures is due to the formation and propagation of wave of magnetic flux annihilation (areas with zero magnetic induction). The relationship between the penetration depth of annihilation front and the external magnetic field at different ambient temperatures, and the temperature dependence of the rate of motion of the front of magnetic flux annihilation, are found. The experimental data qualitatively fit the results from numerical calculations performed using the Monte Carlo method.