Investigation of Phase Relations and Reaction Pathways in Pnictide Superconductors

磷族超导体中相关系和反应路径的研究

• 批准号: 1006584
• 负责人: Eric Hellstrom
• 金额: $ 37.11万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006584&HistoricalAwards=false
• 关键词: Investigation; Phase; Relations; Reaction; Pathways

NON-TECHNICAL DESCRIPTION: In 2008 a new family of high-temperature superconductors that contain Fe and As was discovered. There has been a flurry of work on these and related pnictide superconductors (containing N, P or As) since then and the critical temperature (for operation) has been raised to 55 K. These materials are particularly interesting to the physics community because they have an intriguing combination of magnetic and superconducting properties, and they are of significance to the applied superconductivity community because they appear to have superconducting properties that may make them suitable for practical applications. However, practical applications require high-quality bulk material with clean, well-connected grain boundaries that allow supercurrent to move from grain to grain across the material. The bulk pnictide superconductors made today suffer from severely limiting current transport across grain boundaries due to multiphase mixtures that typically contain a Fe-As phase that covers the grain boundaries.TECHNICAL DETAILS: The intellectual merit of this project lies in investigating phase relations and reaction pathways to understand how to process pnictide superconductors to make high-quality bulk material that has clean, well-connected grain boundaries. Knowing what phases should be present in a sample (phase relations) and what phases are actually present (reaction pathways) guides the development of new heat treatments to make bulk samples. The resulting high-quality samples can be used to evaluate key bulk properties such as the critical current density in polycrystalline samples. This work investigates the Ba-Fe-As- Co system, which contains the Ba(Fe1-xCox)2As2 superconductor. The broader impact of this research is to involve students and teachers in research on pnictide superconductors and expose lay audiences to the wonders of superconductivity and the world of superconductor processing. Specifically, Hellstrom continues to recruit summer students from underrepresented groups and to work with K-12 teachers during the summer. He also gives talks on superconductivity at the Rotary Club and other local civic organizations.

非技术描述：在2008年，一个新的高温超导体系列，其中包含Fe并发现。从那时起，这些和相关的PNICTIDE超导体（包含N，P或AS）就已经进行了一系列工作，并且将临界温度（用于操作）提高到55K。这些材料对物理学界特别有趣，因为它们具有磁性和超导性特性的重要性，并且它们具有适当的特性，并且它们具有适当的属性，因为它们具有适当的超级能力，因为它们具有超级comportive，因为它们具有超级超过的超级能力，因此它们具有适当的性能。申请。但是，实用的应用需要具有清洁，连接良好的晶界的高质量散装材料，这些晶粒边界可以使超电流在整个材料中从谷物转移到谷物。由于多相混合物，通常包含一个涵盖谷物边界的fe-fe，该项目的智力优点在于，该项目的智力优点在于研究阶段关系和反应途径，以了解如何使晶状体相关型构成高度的物质，因此该项目的智力优点在于，该项目的智力优点在于，该项目的智力优点在于，该项目的智力优点在于，该项目的智力优点在于，构成高度的物质，因此，大量的pnictide超导体遭受了严重限制的跨晶界的严重限制。知道样品中应存在什么阶段（相位关系）以及实际存在的阶段（反应途径）指导新的热处理以制造大量样品。所得的高质量样品可用于评估关键的体积特性，例如多晶样品中的临界电流密度。这项工作研究了包含BA（Fe1-XCOX）2AS2超导体的BA-FE-AS-CO系统。 这项研究的更广泛的影响是让学生和教师参与有关PNICTIDE超导体的研究，并向超导性的奇观和超导体加工的世界暴露出来的观众。具体来说，Hellstrom继续从代表性不足的团体中招募夏季学生，并在夏季与K-12老师一起工作。他还在扶轮社和其他当地公民组织就超导性进行了会谈。