Analysis of Superconductor Magnetization Hysteresis

An essential criterion of superconductivity in studied samples is sharp drop of the resistance at some temperature. Other essential criterion is a great diamagnetic response during the magnetization measurements. Temperature and magnetic field dependencies of the magnetization give the detailed characterization of the superconducting phase in single-crystal and polycrystalline samples. The critical state model [1] and its many modifications describe entering and trapping of magnetic flux in a II-type superconductor. The extended critical state model [2–4] accounts contributions to the magnetization loop from the surface and the internal volume of a superconducting sample. The extended model allows to parametrize the magnetization hysteresis with asymmetry relative to the M = 0 axis.