{"title":"High tolerance of the superconducting current to large grain boundary angles in potassium-doped BaFe2As2","authors":"Takafumi Hatano, Dongyi Qin, Kazumasa Iida, Hongye Gao, Zimeng Guo, Hikaru Saito, Satoshi Hata, Yusuke Shimada, Michio Naito, Akiyasu Yamamoto","doi":"10.1038/s41427-024-00561-9","DOIUrl":null,"url":null,"abstract":"<p>Superconducting magnets based on high-temperature superconductors (HTSs) have become critical components in cutting-edge technologies such as advanced medical applications. In HTSs, weak links of superconductivity are inevitable at high-angle grain boundaries (GBs). Thus, two adjacent grains should be crystallographically aligned within the critical angle (<i>θ</i><sub>c</sub>), for which the intergrain critical current density (<i>J</i><sub>c</sub>) starts to decrease exponentially. The <i>θ</i><sub>c</sub> of several iron-based superconductors (IBSs) is larger than that of cuprates. However, the decreases in both <i>θ</i><sub>c</sub> and intergrain <i>J</i><sub>c</sub> under magnetic fields for IBSs are still substantial, hampering their applications in polycrystalline forms. Here, we report that potassium-doped BaFe<sub>2</sub>As<sub>2</sub> (Ba122:K) exhibits superior GB performance to that of previously reported IBSs. A transport <i>J</i><sub>c</sub> of over 0.1 MA/cm<sup>2</sup> across [001]-tilt GBs with misorientation angles up to <i>θ</i><sub>GB</sub> = 24° was recorded even at 28 K, which is a required level for practical applications. Additionally, even in an applied magnetic field, <i>θ</i><sub>c</sub> was unaltered, and the decay of the intergrain <i>J</i><sub>c</sub> was small. Our results highlight the exceptional potential of Ba122:K for polycrystalline applications and pave the way for next-generation superconducting magnets.</p>","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":null,"pages":null},"PeriodicalIF":8.6000,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Npg Asia Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1038/s41427-024-00561-9","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Superconducting magnets based on high-temperature superconductors (HTSs) have become critical components in cutting-edge technologies such as advanced medical applications. In HTSs, weak links of superconductivity are inevitable at high-angle grain boundaries (GBs). Thus, two adjacent grains should be crystallographically aligned within the critical angle (θc), for which the intergrain critical current density (Jc) starts to decrease exponentially. The θc of several iron-based superconductors (IBSs) is larger than that of cuprates. However, the decreases in both θc and intergrain Jc under magnetic fields for IBSs are still substantial, hampering their applications in polycrystalline forms. Here, we report that potassium-doped BaFe2As2 (Ba122:K) exhibits superior GB performance to that of previously reported IBSs. A transport Jc of over 0.1 MA/cm2 across [001]-tilt GBs with misorientation angles up to θGB = 24° was recorded even at 28 K, which is a required level for practical applications. Additionally, even in an applied magnetic field, θc was unaltered, and the decay of the intergrain Jc was small. Our results highlight the exceptional potential of Ba122:K for polycrystalline applications and pave the way for next-generation superconducting magnets.
期刊介绍:
NPG Asia Materials is an open access, international journal that publishes peer-reviewed review and primary research articles in the field of materials sciences. The journal has a global outlook and reach, with a base in the Asia-Pacific region to reflect the significant and growing output of materials research from this area. The target audience for NPG Asia Materials is scientists and researchers involved in materials research, covering a wide range of disciplines including physical and chemical sciences, biotechnology, and nanotechnology. The journal particularly welcomes high-quality articles from rapidly advancing areas that bridge the gap between materials science and engineering, as well as the classical disciplines of physics, chemistry, and biology. NPG Asia Materials is abstracted/indexed in Journal Citation Reports/Science Edition Web of Knowledge, Google Scholar, Chemical Abstract Services, Scopus, Ulrichsweb (ProQuest), and Scirus.