Interfacial intermixing in SrRuO3 /Pr0.7 Ca0.3 MnO3 epitaxial superlattices: A HAADF-STEM study (Phys. Status Solidi A 3∕2014)

Perovskite superlattices show a large variety of useful physical properties, like (anti)ferromagnetism, (anti)ferroelectricity, superconductivity and multiferroicity. These properties may strongly depend on the interface morphology. In the article by Reinald Hillebrand et al. (see pp. 536–542), high angle annular dark field scanning transmission electron micrographs (HAADF-STEM) of SrRuO3/Pr0.7Ca0.3MnO3 (SRO/PCMO) superlattices are interpreted quantitatively. The superlattices were fabricated by pulsed-laser deposition (PLD). The growth was performed at a temperature of 650 °C and in an oxygen partial pressure of 0.14 mbar. The images were taken in the probe-corrected (cs = 0) FEI microscope TITAN 80-300 at 300 kV. The experimental studies have been substantially supported by image simulations. The specimen thickness is estimated by comparing experimental and simulated Z-contrast ratios. The quantitative image analyses proved that the intermixing at the interfaces is different for the growth of SRO on PCMO and that of PCMO on SRO. In addition, the thermal stability of SRO/PCMO superlattices is studied, based on a series of annealing experiments up to 1200 °C.