Doping-depenent specific heat study of the superconducting gap in Ba(Fe1-xCox)2As2

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.81.184518· OSTI ID:988733

Gofryk, K. ^[1]; Sefat, A. S. ^[2]; McGuire, Michael A ^[3]; Sales, Brian C ^[3]; Mandrus, David ^[3]; Thompson, Joe D. ^[1]; Bauer, E. D. ^[1]; Ronning, F. ^[1]

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1. Los Alamos National Laboratory (LANL)
2. Oak Ridge National Laboratory (ORNL)
3. ORNL

We report a doping, magnetic field, and low-temperature-dependent study of the specific heat of the iron-arsenide Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} at underdoped (x=0.045), optimal-doped (x=0.08) and overdoped (x=0.103 and 0.105) regimes. By subtracting the lattice specific heat the temperature and magnetic field dependence of the electronic specific heat has been studied. The temperature and field dependencies of the superconducting part of Cp exhibit similar behavior for all doping concentrations. The temperature variation in the electronic specific heat as well as its field dependence cannot be described by a single isotropic s-wave gap, pointing to a complex gap structure in the system. The lack of doping dependence indicates that the gap structure does not change significantly as a function of doping. We also observe a significant residual linear term of unknown origin in the specific heat of Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} which suggests that inhomogeneity may be an important factor in Co-doped BaFe{sub 2}As{sub 2}.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 988733
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 18 Vol. 81; ISSN 1098-0121; ISSN 1550-235X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARSENIDES
BARIUM COMPOUNDS
COBALT ARSENIDES
DOPED MATERIALS
ELECTRONIC SPECIFIC HEAT
ENERGY GAP
IRON ARSENIDES
SUPERCONDUCTORS