Neutron-irradiation effects in LaO0.9F0.1FeAs superconductor

The effect of atomic disorder induced by neutrons irradiation on superconducting and normal state properties of polycrystalline LaFeAsO0.9F0.1 was investigated. The irradiation of the sample by a “moderate” neutron fluence Φ = 1.6·10 cm at Tirr = 50 ± 10 oC leads to the suppression of superconductivity which recovers almost completely after annealing at temperatures Tann ≤ 750 oC. It is shown that the reduction of superconducting transition temperature Tc under atomic disordering is not determined solely by the value of Hall concentration nH, i.e. doping level, but is governed by the reduction of electronic relaxation timeτ. This behavior can be described qualitatively by universal Abrikosov-Gor’kov equation which presents evidence on the anomalous type of electrons pairing in Fe-based superconductors.