A classification of Fe-pnictide heterointerfaces based on electrostatic principles into initially compensated and uncompensated interfaces is proposed and used for tailoring the interfacial microstructure and superconducting properties. We show that the heterointerface between LnOFeAs (Ln = La, Sm) and BaFe2As2 is nonpolar and remains clean and coherent with Co2+ addition. Co-diffusion results in superconductivity across the whole bilayer. In contrast, IFL formation occurs after adding O2−, and superconductivity with a 2D signature develops with time.
- Silvia Haindl
- Sergey Nikolaev
- Ian MacLaren