Transport properties, upper critical field and anisotropy of Ba(Fe0.75Ru0.25)2As2 single crystals

The temperature and angle dependent resistivity of Ba(Fe0.75Ru0.25)(2)As-2 single crystals were measured in magnetic fields up to 14 T. The temperature dependent resistivity with the magnetic field aligned parallel to c-axis and ab-planes allow us to derive the slope of dH (c2) (ab) /dT and dH (c2) (c) /dT near T (c) yielding an anisotropy ratio Gamma = dH (c2) (ab) /dT/dH (c2) (c) /dT approximate to 2. By scaling the curves of resistivity vs. angle measured at a fixed temperature but different magnetic fields within the framework of the anisotropic Ginzburg-Landau theory, we obtained the anisotropy in an alternative way. Again we found that the anisotropy (m (c) /m (ab) )(1/2) was close to 2. This value is similar to that in Ba0.6K0.4Fe2As2 (K-doped Ba122) and Ba(Fe0.92Co0.08)(2)As-2 (Co-doped Ba122). This suggests that the 3D warping effect of the Fermi surface in Ru-doped samples may not be stronger than that in the K-doped or Co-doped Ba122 samples, therefore the possible nodes appearing in Ru-doped samples cannot be ascribed to the 3D warping effect of the Fermi surface.