公开(公告)号：US06740623B2

公开(公告)日：2004-05-25

申请号：US10350718

申请日：2003-01-24

Applicant: Ayako Yamamoto ,  Wei-Zhi Hu ,  Setsuko Tajima

Inventor： Ayako Yamamoto ,  Wei-Zhi Hu ,  Setsuko Tajima

IPC: C04B10100

CPC classification number: H01L39/2419 ,  H01L39/126 ,  Y10S505/776 ,  Y10S505/779

Abstract: An Hg- or Nd-based oxide superconductor comprises Ba as a constituent element and has a content of carbon as an impurity at a level of not greater than 2.0 atomic % whereby the oxide superconductor stably shows high superconducting characteristics without causing degradation with time. For its production, BaO, which has a reduced content of carbon impurity of 0.5% or below, is provided as a feed stock for Ba, and the starting materials are mixed and processed in a dry atmosphere wherein an amount of a carbon-containing gas is suppressed to a certain level, thereby obtaining the oxide superconductor.

Abstract translation: 作为构成元素的Hg或Nd系氧化物超导体，以不大于2.0原子％的含量的碳为杂质，由此氧化物超导体稳定地表现出高的超导特性，而不会随时间而劣化。 作为Ba的原料，作为Ba的原料提供碳含量低于0.5％以下的BaO，在干燥气氛中混合并加工原料，其中含碳气体 被抑制到一定水平，从而获得氧化物超导体。

公开(公告)号：US06537949B1

公开(公告)日：2003-03-25

申请号：US09517859

申请日：2000-03-03

Applicant: Ayako Yamamoto ,  Wei-Zhi Hu ,  Setsuko Tajima

Inventor： Ayako Yamamoto ,  Wei-Zhi Hu ,  Setsuko Tajima

IPC: H01B1200

CPC classification number: H01L39/2419 ,  H01L39/126 ,  Y10S505/776 ,  Y10S505/779

Abstract: An Hg- or Nd-based oxide superconductor comprises Ba as a constituent element and has a content of carbon as an impurity at a level of not greater than 2.0 atomic % whereby the oxide superconductor stably shows high superconducting characteristics without causing degradation with time. For its production, BaO, which has a reduced content of carbon impurity of 0.5% or below, is provided as a feed stock for Ba, and the starting materials are mixed and processed in a dry atmosphere wherein an amount of a carbon-containing gas is suppressed to a certain level, thereby obtaining the oxide superconductor.

Abstract translation: 作为构成元素的Hg或Nd系氧化物超导体，以不大于2.0原子％的含量的碳为杂质，由此氧化物超导体稳定地表现出高的超导特性，而不会随时间而劣化。 作为Ba的原料，作为Ba的原料提供碳含量低于0.5％以下的BaO，在干燥气氛中混合并加工原料，其中含碳气体 被抑制到一定水平，从而获得氧化物超导体。

公开(公告)号：US06787504B2

公开(公告)日：2004-09-07

申请号：US10333827

申请日：2003-01-23

Applicant: Lee Sergey Romonovich ,  Ayako Yamamoto ,  Setsuko Tajima

Inventor： Lee Sergey Romonovich ,  Ayako Yamamoto ,  Setsuko Tajima

IPC: H01L3924

CPC classification number: C01B35/04 ,  B01J3/062 ,  B01J2203/0605 ,  B01J2203/0645 ,  B01J2203/068 ,  Y10T29/49014 ,  Y10T29/49117

Abstract: The invention is intended to establish means for manufacturing MB2 single crystals and to provide a useful superconductive material (wire rod and so forth) taking advantage of anisotropic superconductive properties thereof. A mixed raw material of Mg and B or a precursor containing MgB2 crystallites, obtained by causing reaction of the mixed raw material of Mg and B, kept in contact with hexagonal boron nitride (hBN), is held at a high temperature in the range of 1300 to 1700° C. and under a high pressure in the range of 3 to 6 GPa to cause reaction for forming an intermediate product, thereby growing the MB2 single crystals having anisotropic superconductive properties via the intermediate product. The single crystals have features such that, depending on a direction in which a magnetic field is applied thereto, an irreversible magnetic field strength becomes equivalent to not less than 95% of a second magnetic field strength, so that adjustment of crystal orientation thereof results in production of a superconductive material excellent in property. Further, it is useful in effecting growth of the single crystals to cause a reducing agent such as Mg and so forth to coexist at the time of the reaction, or to provide a temperature gradient in melt occurring in the course of the reaction.

Abstract translation: 本发明旨在建立用于制造MB2单晶的手段，并且利用其各向异性超导性能提供有用的超导材料（线棒等）。 通过与保持与六方氮化硼（hBN）接触的Mg和B的混合原料的反应获得的Mg和B的混合原料或含有MgB 2微晶的前体在高温下保持在 1300至1700℃，在3至6GPa的高压下引起反应，形成中间产物，从而通过中间产物生长具有各向异性超导性的MB2单晶。 单晶具有这样的特征：根据施加磁场的方向，不可逆磁场强度等于不小于第二磁场强度的95％，从而导致晶体取向的调整 生产性能优异的超导材料。 此外，在进行单晶生长以使Mg等还原剂在反应时共存，或在反应过程中提供熔融温度梯度是有用的。

公开(公告)号：US06599862B2

公开(公告)日：2003-07-29

申请号：US09916175

申请日：2001-07-26

Applicant: Sergey Lee ,  Setsuko Tajima

Inventor： Sergey Lee ,  Setsuko Tajima

IPC: C04B10100

CPC classification number: C04B35/4525 ,  C04B35/4521 ,  H01L39/2477 ,  Y10S505/737 ,  Y10S505/742

Abstract: The invention provides a method for stably preparing a bismuth-based high temperature superconductor of a Bi-2223 single-phase or a Bi/Pb-2223 single phase, wherein a second phase is not allowed to reside, at a low cost and efficiently. With the method described above, mixed powders of raw materials (mixed powders of oxides and carbonates), obtained by mixing the raw materials such that a mixing ratio of constituents, Bi:Sr:Ca:Cu or (Bi, Pb):Sr:Ca:Cu, becomes identical to the stoichiometric ratio of a crystal of the superconductor Bi2Sr2Ca2Cu3Oz, or (Bi, Pb) 2Sr2Ca2Cu3Oz, respectively, are used as raw material for sintering, and the sintering is applied thereto, using KCl as a flux. In this case, the raw material for the sintering as calcinated is preferably used, and the sintering is preferably applied at a sintering temperature kept at a constant level.

Abstract translation: 本发明提供了一种低成本且高效率地稳定地制备Bi-2223单相或Bi / Pb-2223单相的铋基高温超导体的方法，其中不允许第二相存在。 使用上述方法，通过将原料混合使得成分Bi:Sr:Ca:Cu或（Bi，Pb）：Sr:Cb的混合比例得到的原料混合粉末（氧化物和碳酸盐的混合粉末） Ca：Cu分别与超导体Bi2Sr2Ca2Cu3Oz的晶体化学计量比相同，或（Bi，Pb）2Sr2Ca2Cu3Oz分别作为烧结原料，使用KCl作为助熔剂进行烧结。 在这种情况下，优选使用煅烧的烧结原料，烧结温度优选在保持恒定水平的烧结温度下进行。