Fig. 5: Resistive transitions for different Ln-1111/Ba-122 heterostructures.
From: Engineering of Fe-pnictide heterointerfaces by electrostatic principles

a in the presence of Co doping and b for undoped layers, and c the metal-to-superconductor transition with time in the heterostructure with interfacial layer formation. The undoped heterostructure in (b) does not develop superconductivity after time but shows a slightly increased resistance (curves 1, 2). (See also Fig. S8 in SI.) d, e Ginzburg-Landau fit (red curve) for the upper critical fields in Co-doped heterostructures showing 3D superconductivity (90% Rn). f 2D-induced superconducting state in the heterostructure with an interfacial layer fitted by Tinkham’s formula (blue) (80% Rn).