This research is aimed at understanding pinning, dissipative phenomena and magnetic stability in high temperature superconductors (HTSC's). This work includes measurement of hysteretic response, magnetic relaxation and the magnetic irreversibility line in single crystalline and polycrystalline HTSC's. Magnetic properties will be correlated with microstructural features responsible for pinning. Magnetic instabilities (flux jumps) will be explored in large high quality single crystals.
