Development of new oxide superconductors for materials of the MRI magnet wire

MRI磁线材料新型氧化物超导体的研制

基本信息

批准号：
14580815
负责人：
SASAKURA Hiroyuki
金额：
$ 1.86万
依托单位：
HAMAMATSU UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580815/
关键词：
Oxide superconductor New materials Materials for a magnet wire Ru-Sr-Ln(Ce)-Cu-O system 1232 phase Bi(Pb)-Sr-La-Cu-O system 2212 phase Ru-Sr-Ln(Ce)-Cu-O系酸化物高温超伝導体

项目摘要

New materials showing superconductivity at high temperatures have been earnestly desired. They are useful as materials of the wire of the MRI magnet. We have made fundamental researches on synthesis of new superconducting oxides being agreeable to the materials. We show summary of the research results below.We had searched new materials belonging to the Ru-based oxide superconductors, because of their useful nature showing high-T_c superconductivity without such any treatment for hole-doping as annealing under high-pressure O_2 atmosphere. As a result, we succeeded for the first time in synthesis of the 1232 phase showing superconductivity and ferromagnetism in the Ru-Sr-Ln(Ce)-Cu-O system (Ln=Sm, Eu and Gd). Interestingly, he T_c values are increasing as the lattice parameters are becoming small, and the value comes to the maximum one in the case of the sample with Ln=Gd. This result can be expected that the T_c values correlate the lattice parameters. From this expectation, we perfor … More med an experiment of partial substitution of Nb for Ru in the Ru-based 1232 sample with Ln=Gd. Ionic radius of Nb is bigger than that of Ru. Then, we obtained such an experimental result that with increasing of the substituted quantity of Nb, the lattice parameters were increasing, the T_c values were expectedly decreasing. Then, we prepared many samples partially substituted for Gd by Sm, Dy and Ho. As a result, we discovered that the T_c values were increasing, when Dy or Ho with smaller ionic radius were selected for a substituted element. This is one of important experimental facts obtained by us, it suggests that the stress due to the mismatches between the perovskite-type blocks containing the CuO_2 pyramids and the fluorite-type ones existing in the crystal structure affects on the T_c values.Moreover, we have also succeeded in synthesizing new Bi-based superconductor of the 2212 phase by partial substitution of Pb for Sr and/or Bi in the Bi-Sr-La-Cu-O system. The Bi-2212 compound has never been synthesized in the Bi-Sr-La-Cu-O system because of similar values of the ionic radii of Bi^<3+>, Sr^<2+> and La^<3+>. This is also one of important experimental results obtained by us, it shows that our supposed materials can be realized by controlling the ionic radius of the constituent elements. Less

在高温下表现出超导性的新材料已竭尽全力。它们可作为MRI磁铁线的材料。我们已经进行了有关合成新超导氧化物与材料一致的基本研究。我们展示了下面的研究结果的摘要。我们搜索了属于RU基氧化物超导体的新材料，因为它们的有用性质显示出高-T_C超导性，而没有这种对高压O_2大气下退火的任何处理方法。结果，我们首次成功地合成了1232阶段，显示了RU-SR-LN（CE）-CU-O System（LN = SM，EU和GD）中的超导性和铁磁剂。有趣的是，随着晶格参数越来越小，他的T_C值正在增加，并且在ln = gd的样品的情况下，该值最大值。可以预期，T_C值将晶格参数相关联。从这一期望中，我们会进调……在基于Ru的1232样品中，NB部分替代NB的实验是用LN = Gd的。 NB的离子半径大于Ru的离子半径。然后，我们获得了这样的实验结果，以至于随着替换量的NB量增加，晶格参数正在增加，T_C值预计会降低。然后，我们准备了许多用SM，DY和HO部分代替GD的样品。结果，我们发现当选择较小离子半径的Dy或HO以取代元件时，T_C值正在增加。这是我们获得的重要实验事实之一，它表明，由于包含coo_2金字塔的钙钛矿型块之间的不匹配而引起的压力与晶体结构中存在的氟含量的压力会影响T_C值的荧光型型含量。在T_C值上都会影响T_C的替代，我们还通过合成了基于Bi的超级PRE的22121212121212221222122122222222221.和/或BI-SR-LA-LA-CU-O系统中的BI。 BI-2212化合物从未在BI-SR-LA-LA-CU-O系统中合成，因为Bi^<3+>，Sr^<2+>和La^<3+>的离子半径相似。这也是我们获得的重要实验结果之一，它表明我们的预期材料可以通过控制构成元素的离子半径来实现。较少的