The magnetization of PrFeAsO0.60F0.12 superconductor

Research highlights: → The critical current density JL exhibits a second peak well below Hc2(T). → A plateau up to H* followed by H-5/8 behavior of JL(H) is the characteristic of strong pinning. → The pinning force and the density of pinning centers increase with oxygen vacancies. → PrFeAsO0.60F0.12 displays a rich vortex phase diagram. - Abstract: The magnetization of the PrFeAsO0.60F0.12 polycrystalline sample has been measured as functions of temperature and magnetic field (H). The observed total magnetization is the sum of a superconducting irreversible magnetization and a paramagnetic magnetization. Analysis of dc susceptibility χ(T) in the normal state shows that the paramagnetic component of magnetization comes from the Pr3+ magnetic moments. The intragrain critical current density (JL) derived from the magnetization data is large. The JL(H) curve displays a second peak which shifts towards the high-field region with decreasing temperature. In the low-field region, a plateau up to a field H* followed by a power law H-5/8 behavior of JL(H) is the characteristic of the strong pinning. A vortex phase diagram for the present superconductor has been obtained from the magnetization and resistivity data.