Preparation of a high-Jc YBCO bulk superconductor by the platinum doped melt growth method

Ogawa, Naoyuki; Hirabayashi, I.; Tanaka, Shōji

doi:10.1016/0921-4534(91)90304-h

Cited by 231 publications

(72 citation statements)

References 6 publications

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“…This is easily seen in FIGURE 3 where all the elements increase in atomic % with increasing size, or increasing W atomic % except Cu, which instead decreases. It is widely observed in melt-textured YBCO superconductor that large deposits (up to several hundred micrometers in size) of a compound rich in Ba and Cu is a byproduct of the texturing process, e.g., [1][2][3][4][5][6][8][9]. A similar analysis (not shown) of the (W +Pt)-doped samples also concluded that Cu is not a component of the W-Pt-Y-Ba-O particles.…”

Section: Microstructurementioning

confidence: 62%

“…Y211 deposits have been shown to act as pinning centers and increase J C in melt-textured YBCO [1]. Platinum (Pt) [2] or nanometer-size cerium oxide (nano-CeO 2 ) [3] doping into Y123 and Y211 powders, followed by melttexturing, results in Y211 deposits that are reduced in size, and are also elongated in shape. This refinement of Y211 particles in YBCO also increases the number the number of pinning centers, resulting in an increase of J C in bulk YBCO [3].…”

Section: Introductionmentioning

confidence: 99%

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The Puzzle of Two Different Sub-Micrometer Tungsten-Rich Deposits in Bulk Ybco: One Acts as Pinning Centers and the Other Does Not

Sawh¹,

Weinstein²,

Parks³

et al. 2010

AIP Conference Proceedings

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Two types of large grain YBCO samples doped with tungsten oxide, one with platinum and the other without, were produced using a slow cooling process. Observations of the trapped magnetic flux density showed that the flux density of the W-doped, Pt-free samples did not change with W doping levels of up to 2.1 mol%. In contrast, the (W + Pt)-doped samples resulted in a monotonic improvement in trapped magnetic flux density as a function of W doping. Microstructure studies indicate that both types of samples contain profuse sub-micrometer deposits of a W-rich compound. The Pt-free samples contain (W 0.4 Y 0.6 )BaO 3 deposits while the (W + Pt)-doped samples contain deposits of a (W 0.5 Pt 0.5 )YBa 2 O 6 compound. Both types of deposits are of essentially the same size and have comparable number density. The results are strikingly similar to an earlier experiment in which uranium doped, Pt-free, large grain YBCO also did not show any improvement in trapped magnetic flux density. The U-doped, Pt-free samples contain profuse sub-micrometer deposits of a (U 0.4 Y 0.6 )BaO 3 compound, which have been shown to be ferromagnetic. The inability of both the (W 0.4 Y 0.6 )BaO 3 and (U 0.4 Y 0.6 )BaO 3 submicrometer deposits to act as pinning centers in self-field, suggest that this behavior is systematic.

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Section: Microstructurementioning

confidence: 62%

Section: Introductionmentioning

confidence: 99%

The Puzzle of Two Different Sub-Micrometer Tungsten-Rich Deposits in Bulk Ybco: One Acts as Pinning Centers and the Other Does Not

Sawh¹,

Weinstein²,

Parks³

et al. 2010

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…As stated above in the sub-section 2-2, the addition of Pt to precursor powders is very effective for reducing the Y-211 grain growth in a partial molten state and hence fine dispersion of Y-211 in the Y-123 matrices [11]. In melt-process, average size of Y-211 particles become larger in Ba-Cu-O liquid with time according to the Ostwald ripening theory [16], which is not favorable for obtaining high J c .…”

Section: -3 Coarsening Of (Lre)-211 Particlesmentioning

confidence: 97%

“…Here the addition of Pt (typically 0.1-0.5 wt.%) to the precursor powder is very effective for refinement of Y-211 in the liquid, which led to fine dispersion of Y-211 particle in the Y-123 superconducting matrix, hence high J c [11]. CeO 2 powder has been also used instead of Pt for cost-effective production [12].…”

Section: -2 Top-seeded Melt Growth (Tsmg) Processmentioning

confidence: 99%

Nanocomposite RE-Ba-Cu-O Bulk Superconductors

Iida

2015

Oxide Thin Films, Multilayers, and Nanocomposites

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Nanocomposite oxide high-temperature bulk superconductors can be used as "quasi-magnets". Thanks to the recent progress of material processing, "quasi-magnet" with 26 mm diameter can generate a large field of 17.6 T at 26 K. These results are highly attractive for applications, involving levitation of permanent magnets on the bulk superconductors. Indeed, several other applications such as motors and magnetic resonance microscope using bulk superconductors have been proposed and demonstrated. In this chapter, we describe several techniques to improve the magnetic properties for bulk superconductors together with some basics such as phase diagrams and solidifications.

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“…This was just before discovery of Bi-based superconducting material by Dr. Maeda et al [10]. Later on, it was revealed that a small amount of Pt resulted in fine 211 particles about 1μm in size [11][12][13].…”

Section: History Of Qmg and Qmg Bulk Magnetsmentioning

confidence: 99%

History and recent progress of QMG™ and QMG bulk magnets

Morita

2018

J. Phys.: Conf. Ser.

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Abstract. The microstructure of QMG consists of a single crystal REBa 2 Cu 3 O x phase and fine RE 2 BaCuO 5 particles. Y-based QMG was first produced in 1988 by the Quench and Melt Growth method. A bulk magnet made from QMG was proposed in 1989. QMG bulk magnets were realized by enlargement technology using RE substitute seed crystals. Based on these technological innovations, the development of NMR and MDDS, which are product-based applications of bulk magnets, has recently been reported from the research institutes of applied development. The history of the initial development of these QMG materials and QMG bulk magnets was reviewed. In addition, as progress of the recent QMG bulk magnet development, a new reinforcement method for large ring bulk magnets that can trap 10 T class strong magnetic field magnetization has been reported. For high field magnetization, the reinforcement of bulk magnets is essential to prevent cracking due to large hoop force. Compared to the conventional reinforcement method using only the outer metal ring, the new reinforcement method has been developed using thin QMG rings and metal ring sheets as the composite material with the inner and outer metal rings. In the case of the QMG ring reinforced by the conventional method, cracking occurred at 10T magnetization. Whereas the QMG ring created by the new reinforcement method successfully trapped approximately 10 T.

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Preparation of a high-Jc YBCO bulk superconductor by the platinum doped melt growth method

Cited by 231 publications

References 6 publications

The Puzzle of Two Different Sub-Micrometer Tungsten-Rich Deposits in Bulk Ybco: One Acts as Pinning Centers and the Other Does Not

The Puzzle of Two Different Sub-Micrometer Tungsten-Rich Deposits in Bulk Ybco: One Acts as Pinning Centers and the Other Does Not

Nanocomposite RE-Ba-Cu-O Bulk Superconductors

History and recent progress of QMG™ and QMG bulk magnets

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