subject to electron irradiation*

Temperature dependence of in-plane and inter-plane electrical resistivity was studied in single crystals of hole doped iron based superconductor Ba_1−xK_xFe₂As₂ (0≤x≤1). Low temperature (20 K) irradiation with relativistic 2.5 MeV electrons was used to control residual resistivity of the samples. Matthiessen rule is found to be universally violated for all compositions and for both current flow directions. This is in stark contrast with electron doped Ba(Fe_1−xCo_x)₂As₂ [1] and iso-electron substituted BaFe₂(As_1−xP_x)₂ [2].
Possible reasons for Matthiessen rule violation are discussed.

[1] R. Prozorov, et al. NPJ Quantum Materials, 4, 34 (2019).
[2] Yuta Mizukami, et al. J. Phys. Soc. Jpn. 86, 083706 (2017).