Seminarium Międzynarodowego Laboratorium Silnych Pól Magnetycznych i Niskich Temperatur PAN

Effect of pressure on critical parameters and microstructure of doped MgB₂

Grzegorz Gajda

The results of the irreversibility magnetic field and critical temperature were showed for cylindrical sample. These samples were doped with erbium oxide in range from 1-3%. Furthermore, the MgB2 material was made the carbon encapsulated boron. The cylindrical samples were paced in the Nb foil and steel container with dimensions of  6x6 [mm]. The next step were annealed in 1 GPa pressure at 800 oC by 1 h (at argon gas). We show results for samples after HIP process and wi thout HIP process. All the samples were prepared and annealed at the Institute of High Pressure Physics in Warsaw. The measurements of the critical temperature and the hysteresis loop were done at International Laboratory of High Magnetic Fields and Low Temperatures Wroclaw by using a vibrating magnetometer (VSM) up to 14T. The critical current density (Jc) was determined from the Bean model. The calculations allows to determine the pinning force and changes of Jc and Fp in depending on the processing methods. The XRD analysis were made by the Tele @ Radio Research Institute and the Częstochowa University of Technology.