Self-assembling behavior and interface structure in vertically aligned nanocomposite (PrBaMnO):(CeO) films on (001) (La,Sr)(Al,Ta)O substrates.

Heteroepitaxial oxide-based nanocomposite films possessing a variety of functional properties have attracted tremendous research interest. Here, self-assembled vertically aligned nanocomposite (PrBaMnO):(CeO) (x = 0.2 and 0.5) films have been successfully grown on single-crystalline (001) (La,Sr)(Al,Ta)O substrates by the pulsed laser deposition technique. Self-assembling behavior of the nanocomposite films and atomic-scale interface structure between PrBaMnO matrix and CeO nanopillars have been investigated by advanced electron microscopy techniques. Two different orientation relationships, (001)[100]//(001)[1-10] and (001)[100]//(110)[1-10], form between PrBaMnO and CeO in the (PrBaMnO):(CeO) film along the film growth direction, which is essentially different from vertically aligned nanocomposite (PrBaMnO):(CeO) films having only (001)[100]//(001)[1-10] orientation relationship. Both coherent and semi-coherent PrBaMnO/CeO interface appear in the films. In contrast to semi-coherent interface with regular distribution of interfacial dislocations, interface reconstruction occurs at the coherent PrBaMnO/CeO interface. Our findings indicate that epitaxial strain imposed by the concentration of CeO in the nanocomposite films affects the self-assembling behavior of the vertically aligned nanocomposite (PrBaMnO):(CeO) films.