TY - JOUR
T1 - Effect of magnetic field strength in melt-processing on texture development and critical current density of Bi-oxide superconductors
AU - Maeda, H.
AU - Sastry, P. V.P.S.S.
AU - Trociewitz, U. P.
AU - Schwartz, J.
AU - Ohya, K.
AU - Sato, M.
AU - Chen, W. P.
AU - Watanabe, K.
AU - Motokawa, M.
N1 - Funding Information:
The authors would like to thank S.H. Thompson and B. Trociewitz for J c measurements. This research is a part of the project “Creation of Novel Materials in High Magnetic Fields” supported by Japan Science and Technology Corporation. Support at the Florida State University is from the National Science Foundation through the National High Magnetic Field Laboratory and the Office of Navel Research through the Center for Advanced Power Systems.
PY - 2003/4/15
Y1 - 2003/4/15
N2 - Vertical magnetic fields up to 15 T were applied to the magnetic melt-processing (MMP) of Bi2212 bulks and Ag-sheathed tapes with a core thickness above 80 μm, which were set horizontally. Texture with the c-axis along the direction of magnetic field applied during MMP is developed due to the anisotropy in magnetic susceptibility of Bi2212. The degree of texture and the anisotropy factor in magnetization increase almost linearly as the magnetic field strength Ha during MMP is increased. The anisotropy factor in magnetization reaches 6.5 at a Ha of 13 T for Ag-doped Bi2212 bulks, whereas for Bi(Pb)2212 in which Pb partially substitutes for Bi the factor is suppressed to a half of that of Ag-doped Bi2212. The transport critical current Ic and the critical current density Jc of Bi2212 tapes also increase with increasing Ha due to the texture development and Ic reaches above 1000 A in self-filed for the tapes with a core thickness of 180 μm. However, for further thicker tapes, Ic decreases. The suppressions in the Ic for the tapes and in the anisotropy factor in magnetization for Bi(Pb)2212 bulks are due to inhomogeneous melting, and inhomogeneous nucleation and growth of crystals during MMP. When crystal growth is restricted, crystal alignment is suppressed.
AB - Vertical magnetic fields up to 15 T were applied to the magnetic melt-processing (MMP) of Bi2212 bulks and Ag-sheathed tapes with a core thickness above 80 μm, which were set horizontally. Texture with the c-axis along the direction of magnetic field applied during MMP is developed due to the anisotropy in magnetic susceptibility of Bi2212. The degree of texture and the anisotropy factor in magnetization increase almost linearly as the magnetic field strength Ha during MMP is increased. The anisotropy factor in magnetization reaches 6.5 at a Ha of 13 T for Ag-doped Bi2212 bulks, whereas for Bi(Pb)2212 in which Pb partially substitutes for Bi the factor is suppressed to a half of that of Ag-doped Bi2212. The transport critical current Ic and the critical current density Jc of Bi2212 tapes also increase with increasing Ha due to the texture development and Ic reaches above 1000 A in self-filed for the tapes with a core thickness of 180 μm. However, for further thicker tapes, Ic decreases. The suppressions in the Ic for the tapes and in the anisotropy factor in magnetization for Bi(Pb)2212 bulks are due to inhomogeneous melting, and inhomogeneous nucleation and growth of crystals during MMP. When crystal growth is restricted, crystal alignment is suppressed.
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U2 - 10.1016/S0921-4534(02)02237-2
DO - 10.1016/S0921-4534(02)02237-2
M3 - Conference article
AN - SCOPUS:0037445633
SN - 0921-4534
VL - 386
SP - 115
EP - 121
JO - Physica C: Superconductivity and its applications
JF - Physica C: Superconductivity and its applications
T2 - ICMC 2002
Y2 - 16 June 2002 through 20 June 2002
ER -