A doping dependent specific heat study of the superconducting gap in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$

Abstract

We report a doping, magnetic field and low-temperature dependent study of the specific heat of the iron-arsenide Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ at under (x=0.045), optimal (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 $C_p$ exhibit similar behavior for all doping concentrations. The temperature variation of 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${}_{1-x}$Co${}_x$)${}_2$As${}_2$ which suggests that inhomogeneity may be an important factor in Co-doped BaFe${}_2$As${}_2$

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Cited by in corpus (14)

• High-temperature superconductivity in iron-based materials
• Doping evolution of the absolute value of the London penetration depth and superfluid density in single crystals of Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Optical properties of the iron-arsenic superconductor BaFe1.85Co0.15As2
• Effect of annealing on the specific heat of Ba(Fe1-xCox)2As2
• Calorimetric Evidence of Strong-Coupling Multiband Superconductivity in Fe(Te0.57Se0.43) Single Crystal
• Direct observation of local K variation and its correlation to electronic inhomogeneity in (Ba1-xKx)Fe2As2 Pnictide
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Pressure versus concentration tuning of the superconductivity in Ba(Fe(1-x)Cox)2As2
• Anisotropic Phase Diagram and Superconducting Fluctuations in SmFeAsO0.85F0.15
• Superfluid Density and Field-Induced Magnetism in Ba(Fe1-xCox)2As2 and Sr(Fe1-xCox)2As2 Measured with Muon Spin Relaxation
• Calorimetric Evidence for Nodes in the Overdoped Ba(Fe${}_{0.9}$Co${}_{0.1}$)${}_2$As${}_2$
• Theoretical Investigation of Optical Conductivity in Ba [Fe(1-x)Co(x)]2 As2
• ${}^{75}$As NMR of Ba(Fe${}_{0.93}$Co${}_{0.07}$)${}_2$As${}_2$ in High Magnetic Field
• Effect of annealing on the specific heat of optimally doped Ba(Fe${}_{0.92}$Co${}_{0.08}$)${}_2$As${}_2$