© Giada Franceschi/IAP
High-quality surface physics studies require well-defined surfaces, usually single crystals. For many materials of interest, single crystals of sufficient size are not available. Pulsed laser deposition (PLD) is the technique of choice to grow epitaxial films of multielement oxides with well-defined stoichiometry and crystallographic structure. However, the growth of these materials is extremely sensitive to the growth parameters: it is not trivial to obtain crystalline, atomically flat films with the desired composition.
Our lab combines PLD with standard surface science techniques (STM, LEED, XPS, LEIS) to investigate and control the growth of multielement oxides from the most fundamental, atomic-scale, level. We explore how different PLD parameters affect the surface atomic structures of the films, and how, in turn, these affect the growth mechanisms.
The gathered knowledge allows us to grow bulk-like films with atomically flat surfaces suited for UHV investigations of surface processes and reactivity. Examples of epitaxial films grown in our lab are: SrTiO3(110), La0.8Sr0.2MnO3 (LSMO) with (110), and (001) orientations, TiO2 anatase, Ti- and Ni-doped Fe2O3(11̅02), and In2O3(111). These films are currently investigated within our group as well as by international collaborators.
M. Riva, G. Franceschi, Q. Lu, M. Schmid, B. Yildiz, U. Diebold
Pushing the detection of cation nonstoichiometry to the limit
Physical Review Materials 3, 043802 (2019); doi: 10.1103/PhysRevMaterials.3.043802
M. Riva, G. Franceschi, M. Schmid, U. Diebold
Epitaxial growth of complex oxide films: Role of surface reconstructions
Physical Review Research 1, 033059 (2019); doi: 10.1103/PhysRevResearch.1.033059
G. Franceschi, F. Kraushofer, M. Meier, G. S. Parkinson, M. Schmid, U. Diebold, M. Riva
A model system for photocatalysis: Ti-doped α-Fe2O3(11̅02) single-crystalline films
Chemistry of Materials 32, 3753 (2020); doi: 10.1021/acs.chemmater.9b04908
G. Franceschi, M. Wagner, J. Hofinger, T. Krajňák, M. Schmid, U. Diebold, M. Riva
Growth of In2O3(111) thin films with optimized surfaces
Physical Review Materials 3, 103403 (2019); doi: 10.1103/PhysRevMaterials.3.103403
Senior Scientist Michele Riva PhD
Research Unit of Surface Physics