Pulse magnetization and voltage-current characteristic of YBa2Cu3O7-x film

The measurements of YBa2Cu3O7-X films magnetization are made at ramp rate of the external magnetic field up to 105 T/sec at temperature of liquid nitrogen in fields up to 4 T. The linear dependence of the magnetic moment of films on rate of an external magnetic confirms, that in the large electrical fields down to 1 V/cm the voltage-current characteristic can be described by the flux flow resistance Rflow and the critical current Jflow, similar to traditional low temperature superconductors: E = Rflow·(J − Jflow)·Θ(J − Jflow), where θ is the Heaviside function. The experimental data of pulse magnetization of films of thickness 0,2 microns on substrates Al2O3 of size 10 × 10 mm with critical currents higher 106 A/cm2 have allowed to determine field dependence of the critical current and the flux flow resistance. In particular the resistance Rflow is increased approximately by 3 times for increase of an external field from 0,5 up to 4 T, and the Jflow values approach the critical currents determined from quasi-stationary magnetization.