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The ab-plane resistivity and Hall effect are studied in Fe 1−y M y Te 0.65 Se 0.35 single crystals doped with two transition-metal elements, M = Co or Ni, over a wide doping range, 0 y 0.2. The superconducting transition temperature, T c , reaches zero for Co at y 0.14 and for Ni at y 0.032, while the resistivity at the T c onset increases weakly with Co doping, and strongly with Ni doping. The Hall coefficient R H , positive for y = 0, remains so at high temperatures for all y, while it changes sign to negative at low T for y > 0.135 (Co) and y > 0.06 (Ni). The analysis based on a two-band model suggests that at high T residual hole pockets survive the doping, but holes get localized upon the lowering of T , so that the effect of the electron doping on the transport becomes evident. The suppression of the T c by Co impurity is related to electron doping, while in the case of the Ni impurity strong electron localization most likely contributes to fast decrease of the T c .

We present the results of electrical transport measurements of La1.85Sr0.15Cu1−yNiyO4 thin singlecrystal films at magnetic fields up to 9 T. Adding Ni impurity with strong Coulomb scattering potential to slightly underdoped cuprate makes the signs of resistivity saturation at ρsat visible in the measurement temperature window up to 350 K. Employing the parallel-resistor formalism reveals that ρsat is consistent with classical Ioffe-Regel-Mott limit and changes with carrier concentration n as ρsat ∝ 1/ √ n. Thermopower measurements show that Ni tends to localize mobile carriers, decreasing their effective concentration as n ∼ = 0.15 − y. The classical unmodified Kohler's rule is fulfilled for magnetoresistance in the nonsuperconducting part of the phase diagram when applied to the ideal branch in the parallel-resistor model.