Doping evolution of antiferromagnetism and transport properties in nonsuperconducting BaFe2−2xNixCrxAs2
We report elastic neutron scattering and transport measurements on the Ni and Cr equivalently doped iron pnictide BaFe2−2xNixCrxAs2. Compared with the electron-doped BaFe2−xNixAs2, the long-range antiferromagnetic (AF) order in BaFe2−2xNixCrxAs2 is gradually suppressed with vanishing ordered moment and Néel temperature near x=0.20 without the appearance of superconductivity. A detailed analysis on the transport properties of BaFe2−xNixAs and BaFe2−2xNixCrxAs2 suggests that the non-Fermi-liquid behavior associated with the linear resistivity as a function of temperature may not correspond to the disappearance of the static AF order. From the temperature dependence of the resistivity in overdoped compounds without static AF order, we find that the transport properties are actually affected by Cr impurity scattering, which may induce a metal-to-insulator crossover in highly doped BaFe1.7−yNi0.3CryAs2.