Anisotropic Ginzburg–Landau scaling of H_c2 and transport properties of 112-type Ca_0.8La_0.2Fe_0.98Co_0.02As₂ single crystal

High-quality single crystal Ca_0.8La_0.2Fe_0.98Co_0.02As₂ has been successfully synthesized using a self-flux method. The magnetization measurement reveals a second peak effect and high critical current density $J_c$ exceeding 2 × 10⁶ A cm⁻² at 5 K (self-field). The upper critical field anisotropy was systematically studied by measuring the electrical resistivity under various magnetic fields and angles. The angle-dependent magnetoresistance, by choosing an appropriate anisotropy parameter within the framework of the anisotropic Ginzburg–Landau (AGL) theory, can be scaled onto one single curve. In the normal state, the negative Hall coefficient shows strong but nonmonotonic T-dependence through a minimum at ∼175 K. Moreover, it is shown that the magnetoresistance apparently violates the semiclassical Kohler's rule below ∼175 K but can be well scaled by the Hall angle instead. This suggests either a change of carriers with T or exotic anisotropic scattering in the system. (paper)