Selected Publications

Evidence of d-wave superconductivity in K1−xNaxFe2As2 (x = 0, 0.1) single crystals from low-temperature specific-heat measurements

M. Abdel-Hafiez, V. Grinenko, S. Aswartham et al

From the measurement and analysis of the specific heat of high-quality K1−xNaxFe2As2 single crystals we establish the presence of large T 2 contributions with coefficients αsc ≈ 30 mJ/mol K3 at low T for both x = 0 and x = 0.1. Together with the observed √B behavior of the specific heat in the superconducting state both findings give evidence of d-wave superconductivity on almost all Fermi-surface sheets with an average gap amplitude of
0 in the range of 0.4–0.8 meV. The derived Δ0 and observed Tc agree well with the values calculated within Eliashberg theory, adopting a spin-fluctuation mediated pairing in the intermediate coupling regime.

Phys. Rev. B (rapid comm.) 87, 180507(R) (2013)

doi: 10.1103/PhysRevB.87.180507