Magnetization Relaxation of YBa_2Cu_3O_(7－x) Single Crystals in High Magnetic and Electric Fields

摘要

Magnetic properties of high-T_c superconductor YBa_2Cu_3O_(7－x) and their dependencies on the magnetic field variation rate (from 2·10~2 up to 3·10~4 T/s) have been investigated in pulsed magnetic fields up to 35 T, parallel to the ab plane of the crystals. A dependence of fast magnetization relaxation on the high electric field (from 10~(－1) to 10 V/m) has been revealed and studied for the case of electric current directed along the c axis and for a vortex movement parallel to the ab plane. A pronounced peak effect accompanying such movement has been observed over a wide range of magnetic and electric fields including the flux creep to flux flow transition region. The peak effect origin is discussed in connection with this observation.