H+ irradiation effect in Co-doped BaFe2As2 single crystals

We report the suppression of the critical temperature Tc in single crystalline Ba(Fe1−xCox)2As2 at under-, optimal-, and over-doping levels by 3 MeV proton irradiation. Tc decreases and residual resistivity increases monotonically with increasing the dose. The low-temperature resistivity does not show the upturn in contrast with the α-particle irradiated NdFeAs(O,F), which suggests that proton irradiation introduces nonmagnetic scattering centers. Critical scattering rates for all samples obtained by three different ways are much higher than that expected in s±-pairing scenario based on inter-band scattering due to antiferro-magnetic spin fluctuations.

► The effect of H+ irradiation on the suppression of Tc in Co-doped BaFe2As2.
► H+ irradiation introduces nonmagnetic scattering centers.
► Critical Scattering rate is much higher than that expected in s±-pairing scenario.