Fig. 4. Magnetic transport properties and the upper critical fields (H_c2) anisotropy of superconducting R-N₈/S₂ superlattice film.

Temperature dependence of the resistivity under different magnetic fields from 0 to 9 T (a) along c-axis and (b) in the a-b plane below 60 K. c Temperature dependence of (H_c)² (μ₀H || ab) and H_c (μ₀H || c) near T_c. The purple and blue dashed lines are the corresponding linear fits. d Temperature dependence of the upper critical fields for both directions. The solid line is the data fitted around the T_c using the (modified) GL theory, and the dashed lines indicate the Pauli limit of H_Pauli = 1.86 T_c0. e Magnetic field dependence of the resistance measured with different magnetic field orientations at 5 K, and the top right inset shows a configuration for measurements. f Polar angular dependence of the critical magnetic field H_c2(θ) at T = 5 K. The red solid line and the blue dotted line are the fittings with the 2D-Thikham model and the 3D anisotropic G-L model. All the H_c2 data are extracted at 50% of the normal state resistance or resistivity.