We present low-temperature specific heat of the electron-doped Ba(Fe 0.9Co0.1)2As2, which does not show any indication of an upturn down to 400 mK, the lowest measuring temperature. The lack of a Schottky-like feature at low temperatures or in magnetic fields up to 9 T enables us to identify enhanced low-temperature quasiparticle excitations and to study anisotropy in the linear term of the specific heat. Our results cannot be explained by a single or multiple isotropic superconducting gap, but are consistent with multi-gap superconductivity with nodes on at least one Fermi surface sheet. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
Publication Source (Journal or Book title)
New Journal of Physics
Jang, D., Vorontsov, A., Vekhter, I., Gofryk, K., Yang, Z., Ju, S., Hong, J., Han, J., Kwon, Y., Ronning, F., Thompson, J., & Park, T. (2011). Calorimetric evidence for nodes in the overdoped Ba(Fe0.9Co 0.1)2As2. New Journal of Physics, 13 https://doi.org/10.1088/1367-2630/13/2/023036