Growth rate of YBCO single grains containing Y-2411(M)

Y-Ba-Cu-O (YBCO) single grains have the potential to generate large trapped magnetic fields for a variety of engineering applications, and research on the processing and properties of this material has attracted world-wide interest. In particular, the introduction of flux pinning centres to the large grain microstructure to improve its current density, Jc, and hence trapped field, has been investigated extensively over the past decade. Y 2Ba4CuMOx [Y-2411(M)], where M = Nb, Ta, Mo, W, Ru, Zr, Bi and Ag, has been reported to form particularly effective flux pinning centres in YBCO due primarily to its ability to exist as nano-size inclusions in the superconducting phase matrix. However, the addition of the Y-2411(M) phase to the precursor composition complicates the melt-processing of single grains. We report an investigation of the growth rate of single YBCO grains containing Y-2411(Bi) phase inclusions and Y2O3. The superconducting properties of these large single grains have been measured specifically to investigate the effect of Y2O3 on broadening the growth window of these materials

Effect of magnetic field processing on the microstructure of carbon nanotubes doped MgB2

The carbon nanotubes (CNTs) doped MgB2 bulks were sintered in the 5 T pulsed magnetic field at 800 °C for 30 min. The critical temperature (Tc) is 36.3 K, a little higher than that of the bulks sintered without magnetic field, 35.7 K. The critical current density (Jc) shows anisotropy in high measurement magnetic field. The Jc at 20 K increase in high field region when the measurement magnetic field is perpendicular to the sintering magnetic field