Optical properties of BaFe2-xCoxAs2
Département de Physique de la Matière Condensée, Université de Genève - quai Ernest-Ansermet 24, CH1211, Genève 4, Switzerland
2 Van der Waals-Zeeman Institute, University of Amsterdam - NL-1018XE Amsterdam, The Netherlands, EU
Corresponding author: firstname.lastname@example.org
Accepted: 3 May 2010
We present detailed temperature-dependent optical data on BaFe2-xCoxAs2 (BCFA), with x = 0.14, between 4 meV and 6.5 eV. We analyze our spectra to determine the main optical parameters and show that in this material the interband conductivity already starts at energies as low as 10 meV. We determine the superfluid density ρs/(2πc)2 = 2.2±0.5 107 cm-2, which places optimally doped BFCA close to the Uemura line. Our experimental data shows clear signs of a superconducting gap with 2Δ1 = 6.2±0.8 meV. In addition, from comparing the experimental spectra to model calculations we obtain indications for an additional band of strongly scattered carriers with a larger gap, 2Δ2 = 14±2 meV.
PACS: 74.25.Gz – Optical properties / 74.25.-q – Properties of superconductors / 74.70.Xa – Pnictides and chalcogenides
© EPLA, 2010