Nanometer Cerium: A Significant Improvement
over Platinum in Bulk YBCO Superconductor

Ravi-Persad Sawh, Roy Weinstein,
Drew Parks, and Victor Obot

Abstract— Large grain YBCO superconductors, containing the same atomic percentage of Ce, and that of Pt, were produced via the melt-texturing process. Samples doped with nanometer cerium oxide exhibits an approximate 30 % increase in trapped magnetic flux density, relative to platinum doped YBCO. A 30 % increase in trapped magnetic flux density represents ~ 80 % increase in critical current density. Microstructure studies indicate that just like Pt, Ce refines Y211 particles to increase trapped magnetic flux density and critical current density. Cerium is much cheaper than platinum and is therefore, a desirable alternative to Pt in the large-scale production of bulk YBCO superconductors. Another interesting result of this experiment is that the trap magnetic flux density of Ce-doped samples is unchanging over a large range of melting temperatures used for melt-texturing. In addition to refined Y211, Ce-rich deposits are also formed. The Ce-rich particles are insufficient in number to act as effective pinning centers.

Index Terms—Enhancement in critical current density; melt-textured high temperature superconductors; nanometer cerium oxide doping; platinum doping.

Manuscript received 15 August 2008. This research was funded by grants from the U.S. Army Research Office, and the State of Texas, through the Texas Center for Superconductivity at the University of Houston, and the Welch Foundation.
Ravi-Persad Sawh (phone: 713-743-3600; fax: 713-747-4526; e-mail: rsawh@uh.edu), Roy Weinstein and Drew Parks are with the Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204.
Victor Obot is with the Department of Mathematics, Texas Southern University, Houston, TX 77004.

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