Gap structure in the electron-doped iron-arsenide superconductor Ba(Fe0.92Co0.08)2As2: low-temperature specific heat study

被引：40

作者：

Gofryk, K. ^{[1
]}

Sefat, A. S. ^{[2
]}

Bauer, E. D. ^{[1
]}

McGuire, M. A. ^{[2
]}

Sales, B. C. ^{[2
]}

Mandrus, D. ^{[2
]}

Thompson, J. D. ^{[1
]}

Ronning, F. ^{[1
]}

机构：

[1] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

[2] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN 37831 USA

来源：

NEW JOURNAL OF PHYSICS | 2010年 / 12卷

关键词：

WAVE SUPERCONDUCTORS; PAIRING SYMMETRY;

D O I：

10.1088/1367-2630/12/2/023006

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

In this paper, we report the field and temperature dependence of low-temperature specific heat down to 400 mK and in magnetic fields up to 9 T of the electron-doped Ba(Fe0.92Co0.08)(2)As-2 superconductor. Using the phonon specific heat obtained from pure BaFe2As2, we found a normal state Sommerfeld coefficient of 18 mJ mol(-1) K-2 and a condensation energy of 1.27 J mol(-1). The temperature dependence of electronic specific heat clearly indicates the presence of low-energy excitations in the system. The magnetic field variation of field-induced specific heat cannot be described by single clean s- or d-wave models. Rather, the data require an anisotropic gap scenario that may or may not have nodes. We discuss the implications of these results.

引用

页数：10

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