Measurements of the superconducting fluctuations in optimally-doped   BaFe$_{2-x}$Ni$_x$As$_2$ under high magnetic fields: Probing the 3D   anisotropic Ginzburg-Landau approach
  The superconducting fluctuations well inside the normal state of Fe-based superconductors were experimentally studied through the in-plane paraconductivity in several high-quality optimally-doped BaFe$_{2-x}$Ni$_x$As$_2$ crystals. These measurements were performed in magnetic fields with amplitudes up to 14 T, and different orientations relative to the crystals c axis (0, 53 and 90 degrees). The results allowed a stringent check of the applicability of a recently proposed Ginzburg-Landau approach for the fluctuation electrical conductivity of 3D anisotropic materials in presence of finite applied magnetic fields. 
R.I. Rey, A. Ramos-\'Alvarez, C. Carballeira, J. Mosqueira, F. Vidal,   S. Salem-Sugui Jr., A.D. Alvarenga, Rui Zhang, Huiqi...
cond-mat.supr-con