Microstructure of laser-ablated superconducting La2CuO4Fx thin films on SrTiO3

Thin films of lanthanum cuprate were grown on SrTiO3 substrates by pulsed l aser deposition and made superconducting (T-c similar to 38 K) through the process of post-deposition fluorination using elemental fluorine. A microst ructural analysis showed that the [110] zone of the film grows parallel to the [(1) over bar 00] zone of the SrTiO3 substrate, reducing the lattice mi smatch from 37.5% to 2.4%. At the film-substrate interface there is an inte rmediate layer 3-4 nm thick and twin-related grains emanate from this regio n. Stacking faults are present in the bulk of the film, with misoriented su bgrains present at the deposit surface.