The investigation of magnetic flux dynamics in the bulk HTS with the levitation techniques

We have developed an approach for the calculation of interactions in systems with bulk melt-textured high temperature superconductors (HTSC) and permanent magnets (PM). The non-contact resonance oscillations technique was modified to determine ‘under surface’ critical currents in these materials. Two parts of the ac energy losses in such HTSC, hysteretic and viscous ones, were separated from their amplitude dependencies. We have shown that the energy losses were largely determined by the magnetic properties of the HTS sample but the elastic properties of a PM-HTSC system are determined from the topology of the superconducting domains.