Study of vortex state in magnesium diboride superconductors -A vortex matter phase diagram originating from two superconducting gap

二硼化镁超导体中涡旋态的研究——源自两个超导间隙的涡旋物质相图

• 批准号: 20540343
• 负责人: NOJIMA Tsutomu
• 金额: $ 3万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2008
• 资助国家: 日本
• 起止时间: 2008 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20540343/
• 关键词: ホウ化物超伝導体; 渦糸相転移; 渦糸相図; 多ギャップ超伝導; 磁気トルク測定; 元素置換効果; ポイントコンタクト

We studied the vortex matter phase diagram in MgB2, which has been known as a typical two-gap superconductor, and the impurity effect on it. In addition to clarifying the universal characteristics of vortex phase transitions, which have been remarkably observed in high-Tc cuprate superconductors, we found a new type of transition in the vortex state and a modulation of the phase diagram due to Al substitution, which were considered to be peculiar to this system. We also succeeded in measuring the two kinds of gap energies in Ba(Fe0.93Co0.07)2As2, which is related materials of MgB2.

研究了典型双间隙超导体MgB2的涡旋物质相图，以及杂质对其的影响。除了阐明在高tc铜超导体中显著观察到的涡旋相变的普遍特征外，我们还发现了涡旋态的一种新型转变和由于Al取代而引起的相图调制，这被认为是该体系所特有的。我们还成功地测量了MgB2相关材料Ba(Fe0.93Co0.07)2As2的两种间隙能。

项目成果

磁束shaking法を用いたMgB_2単結晶の磁束相転移の観測II

磁通振荡法观察MgB_2单晶磁通相变II

• 发表时间: 2009
• 作者: 長徳峰美;他
• 通讯作者: 他

Observation of magnetization step at order-disorder transition in MgB_2 single crystals

MgB_2单晶有序-无序转变时磁化阶跃的观察

• 发表时间: 2009
• 期刊: Physica C Vol.469, Issues 15-20
• 作者: T.Nojima;K.Takahashi;M.Chotoku;A.Ochiai;H.Aoki;H.-G.Lee;S.-I.Lee
• 通讯作者: S.-I.Lee

MgB_2単結晶のH-T相図-渦糸相転移と多バンド効果-

MgB_2单晶的H-T相图-涡旋相变和多带效应-

• 发表时间: 2010
• 作者: 土浦宏紀;小形正男;R.H.He;野島勉
• 通讯作者: 野島勉

Phase transitions and a supercooling phenomenon of the vortex matter in MgB_2 single crystals

MgB_2单晶中涡旋物质的相变和过冷现象

• 发表时间: 2009
• 作者: S.-H. Lee;Guangyong Xu;W. Ku;J. S. Wen;C. C. Lee;N. Katayama;Z. J. Xu;S. Ji;Z. W. Lin;G. D. Gu;H.-B. Yang;P. D. Johnson;Z.-H. Pan;T. Valla;M. Fujita;T. J. Sato;S. Chang;K. Yamada;and J. M. Tranquada;S. Ebisu;野島勉;H. Tsuchiura;M.Minematsu;野島勉
• 通讯作者: 野島勉

Superconducting anisotropy in single-crystalline Ba(Fe_<0.9>Co_<0.1>)_2As_2 near Tc

Tc附近单晶Ba(Fe_<0.9>Co_<0.1>)_2As_2的超导各向异性

• 发表时间: 2009
• 作者: S.-H. Lee;Guangyong Xu;W. Ku;J. S. Wen;C. C. Lee;N. Katayama;Z. J. Xu;S. Ji;Z. W. Lin;G. D. Gu;H.-B. Yang;P. D. Johnson;Z.-H. Pan;T. Valla;M. Fujita;T. J. Sato;S. Chang;K. Yamada;and J. M. Tranquada;S. Ebisu;野島勉;H. Tsuchiura;M.Minematsu;野島勉;M.Enoki;野島勉;Y.Honda
• 通讯作者: Y.Honda