(ferromagnet - superconductor - ferromagnet) superlattice.
The thin films in this superlattice are grown epitaxially (atom on atom). The diffrence of the unit-cell parameters in different materials result in an epitaxial strain that is accomodated by the antiphase boundary in the ferromagnet (vertical dark stripe in the lowest layer).
The image taken in a scanning transmission electron microscope (STEM).
In this high angle annular dark field (HAADF) image the heavier atoms (La) are brighter/larger than the lighter atoms (Mn or Cu). Very light atoms like oxygen are not visible.
EELS map of a ferromagnet - superconductor - ferromagnet superstructure.
This map enebles the determination of the interfaces, as shown in the sketch below.
Left: HAADF image with the area where EELS spectra is taken.
Right: Simultaneous ADF image and elemental maps.
Bottom: Sketch of te PLCMO/YBCO interface based on the EELS data above
Defects in crystalline structures that are the consequence of epitaxial strain
