Effect of radiation defects on the magnetotransport properties of Ba(Fe$_{1-x}$Co$_x$As)$_2$ high-temperature superconductor

The effect of 200 keV He$^+$ ion irradiation on the transport properties of films of the iron-based Ba(Fe$_{1-x}$Co$_x$As)$_2$ superconductor has been studied. Contributions to the resistivity and magnetoresistance of irradiated samples from scattering by magnetic and nonmagnetic defects have been separated. It has been shown that mainly nonmagnetic defects are generated in the sample under the corresponding irradiation conditions. This result is important in view of the use of the radiation technique for the study of the effect of defects on the properties of iron-based superconductors.