Monarkha V. Low density magnetic flux dynamics in cuprate HTSC single crystals.

The dissertation is devoted to the research of low density captured magnetic flux dynamics in cuprate HTS single crystal samples. A significant growth of the effective pinning potential by a few orders of magnitude has been discovered in 1Oe magnetic field range for RE-123 single crystal samples containing twin boundaries, compared to several kOe range magnetic fields. The behavior of the effective pinning potential has been studied in the case of locally trapped magnetic fields. The effect of natural and artificial dot pinning centers on the magnetic flux creep in Nd-123 single crystals has been studied. The applicability of different flux creep models to the results obtained has been studied.