Isotropic multi-gap superconductivity in BaFe1.9Pt0.1As2 from thermal transport and spectroscopic measurements

摘要: Thermal conductivity, point contact spectroscopy, angle-resolved photoemission and Raman spectroscopy measurements were performed on BaFe1.9Pt0.1As2 single crystals obtained from the same synthesis batch in order to investigate superconducting energy gap structure using multiple techniques. Low temperature thermal conductivity was measured state as a function of magnetic field, revealing an absence quasiparticle excitations limit up 15 T applied fields. Point-contact Andreev reflection needle-anvil technique, yielding features conductance spectra at both 2.5 meV 7.0 scales consistent with multi-gap scenario. Angle-resolved probed electronic band above below transition Tc = 23 K, isotropic magnitude electron hole pockets. Finally, used probe channels, showing threshold scale 3 Tc. Overall, we find strong evidence for no nodes or deep minima this system, consistently observed second, larger suggested by point-contact measurements. We discuss implications that combination these results reveal about parameter BaFe2?xPtxAs2 doping system how relates similar substituted iron pnictides.