Specific heat and phase diagrams of single crystal iron pnictide superconductors
文献类型：期刊论文
| 作者 | Welp, U ; Mu, G ; Xie, R ; Koshelev, AE ; Kwok, WK ; Luo, HQ ; Wang, ZS ; Cheng, P ; Fang, L ; Ren, C ; Wen, HH |
| 刊名 | PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
 |
| 出版日期 | 2009 |
| 卷号 | 469期号:9-12页码:575 |
| 关键词 | D-WAVE SUPERCONDUCTORS QUASI-PARTICLE SPECTRUM LAYERED SUPERCONDUCTOR FIELD YBA2CU3O7-DELTA BA0.6K0.4FE2AS2 LAO1-XFXFEAS TRANSITION COMPOUND GAPS |
| ISSN号 | 0921-4534 |
| 通讯作者 | Welp, U (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. |
| 中文摘要 | We present specific heat measurements on single crystals of the pnictide superconductors NdFeAsO(1-x)F(x) and Ba(1-x)K(x)Fe(2)As(2). Low-temperature measurements on Ba(1-x)K(x)Fe(2)As(2) reveal that the Sommerfeld coefficient of the quasiparticle specific heat increases linearly with applied magnetic field. This is the signature of a fully gapped superconducting state as is expected for instance in the extended s-wave scenario. The large value of the normal state Sommerfeld coefficient indicates a large electronic density of states and significant mass enhancements. We determine the phase diagram using an entropy conserving construction, which does not require the choice of a resistivity criterion to define the transition temperature. Both materials display clear mean-field steps in the specific heat at T(c) of 47 K and 34.6 K, respectively, proving bulk superconductivity. They are characterized by a low superconducting anisotropy near T(c) of Gamma similar to 4 for NdFeAsO(1-x)F(x) and 2.6 for Ba(1-x)K(x)Fe(2)As(2), which is promising for potential applications. We observe extraordinarily high upper critical field slopes of mu(0)partial derivative H(c2)(c)/partial derivative T = -6.5 T/K and mu(0)partial derivative H(c2)(ab)/partial derivative T = -17.4 T/K for Ba(1-x)KxFe(2)As(2) which points to the emergence of paramagnetic limiting effects at low temperatures, A thermodynamic analysis reveals that this material is extreme type-II with kappa(c) similar to 100 and K(ab) similar to 260. (C) 2009 Published by Elsevier B.V. |
| 收录类别 | SCI |
| 资助信息 | US Department of Energy - Basic Energy Science [DE-AC02-06CH11357]; Natural Science Foundation of China; Ministry of Science and Technology of China [2006CB60100, 2006CB921802, 2006CB921107]; Chinese Academy of Sciences (Project ITSNEM). |
| 语种 | 英语 |
| 公开日期 | 2013-09-24 |
| 源URL | [http://ir.iphy.ac.cn/handle/311004/52821]  |
| 专题 | 物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文 |
| 推荐引用方式 GB/T 7714 | Welp, U,Mu, G,Xie, R,et al. Specific heat and phase diagrams of single crystal iron pnictide superconductors[J]. PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS,2009,469(9-12):575. |
| APA | Welp, U.,Mu, G.,Xie, R.,Koshelev, AE.,Kwok, WK.,...&Wen, HH.(2009).Specific heat and phase diagrams of single crystal iron pnictide superconductors.PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS,469(9-12),575. |
| MLA | Welp, U,et al."Specific heat and phase diagrams of single crystal iron pnictide superconductors".PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS 469.9-12(2009):575. |
入库方式： OAI收割
来源：物理研究所
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