2009 年 78 巻 12 号 p. 123702
We investigate the in-plane transport properties of the electron-doped iron arsenide superconductor Ba(Fe1−xCox)2As2 (0≤x≤1). We observe a non-Fermi-liquid behavior characterized by an incoherent resistivity and a low-temperature increase in Hall coefficient (RH) at x≤0.14. We discuss this feature in terms of antiferromagnetic fluctuations. We find that the effective carrier density per Fe/Co atom neff=−V⁄(eRH) (V is the volume per Fe/Co atom and e is the elementary electric charge) at 250 K exhibits a nonmonotonic x dependence with a minimum value at x∼0.1, which is considered to reflect the disappearance of hole Fermi surfaces. We discuss the interrelationships among superconductivity, magnetism, and band nesting.